diff --git a/.gitea/workflows/deploy.yaml b/.gitea/workflows/deploy.yaml
index 74c9d6f..d66c6bf 100644
--- a/.gitea/workflows/deploy.yaml
+++ b/.gitea/workflows/deploy.yaml
@@ -11,6 +11,14 @@ jobs:
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4
+      - name: Test backend
+        uses: actions/setup-python@v6
+        with: 
+          python-version: "3.10"
+      - run: |
+          python -m pip install --upgrade pip
+          pip install -r back/requirements.txt
+          pytest -sv
       - name: Build & deploy
         run: |
           docker compose -f docker-compose.yaml up -d --build
diff --git a/backend/requirements.txt b/backend/requirements.txt
index 68f36e9..542999a 100644
--- a/backend/requirements.txt
+++ b/backend/requirements.txt
@@ -1,33 +1,39 @@
+alembic==1.18.4
 annotated-doc==0.0.4
 annotated-types==0.7.0
 anyio==4.12.1
 brotli==1.2.0
-certifi==2026.1.4
+certifi==2026.2.25
 cffi==2.0.0
 charset-normalizer==3.4.4
 click==8.3.1
+coverage==7.13.4
 cryptography==46.0.5
 cssselect2==0.9.0
 dnspython==2.8.0
 email-validator==2.3.0
-fastapi==0.129.0
-fastapi-cli==0.0.23
+fastapi==0.133.0
+fastapi-cli==0.0.24
 fastapi-cloud-cli==0.13.0
 fastar==0.8.0
 fonttools==4.61.1
-greenlet==3.3.1
+greenlet==3.3.2
 h11==0.16.0
 httpcore==1.0.9
 httptools==0.7.1
 httpx==0.28.1
 idna==3.11
+iniconfig==2.3.0
 Jinja2==3.1.6
 lxml==6.0.2
+Mako==1.3.10
 markdown-it-py==4.0.0
 MarkupSafe==3.0.3
 mdurl==0.1.2
 odfdo==3.20.2
+packaging==26.0
 pillow==12.1.1
+pluggy==1.6.0
 psycopg2-binary==2.9.11
 pycparser==3.0
 pydantic==2.12.5
@@ -38,21 +44,24 @@ pydyf==0.12.1
 Pygments==2.19.2
 PyJWT==2.11.0
 pyphen==0.17.2
+pytest==9.0.2
+pytest-cov==7.0.0
+pytest-mock==3.15.1
 python-dotenv==1.2.1
 python-multipart==0.0.22
 PyYAML==6.0.3
 requests==2.32.5
-rich==14.3.2
-rich-toolkit==0.19.4
+rich==14.3.3
+rich-toolkit==0.19.7
 rignore==0.7.6
 sentry-sdk==2.53.0
 shellingham==1.5.4
-SQLAlchemy==2.0.46
-sqlmodel==0.0.34
+SQLAlchemy==2.0.47
+sqlmodel==0.0.37
 starlette==0.52.1
 tinycss2==1.5.1
 tinyhtml5==2.0.0
-typer==0.24.0
+typer==0.24.1
 typing-inspection==0.4.2
 typing_extensions==4.15.0
 urllib3==2.6.3
@@ -63,4 +72,3 @@ weasyprint==68.1
 webencodings==0.5.1
 websockets==16.0
 zopfli==0.4.1
-alembic==1.18.4
\ No newline at end of file
diff --git a/backend/src/auth/auth.py b/backend/src/auth/auth.py
index 2bf2614..6abb4ba 100644
--- a/backend/src/auth/auth.py
+++ b/backend/src/auth/auth.py
@@ -77,8 +77,8 @@ def callback(code: str, session: Session = Depends(get_session)):
     response = requests.post(TOKEN_URL, data=data, headers=headers)
     if response.status_code != 200:
         raise HTTPException(
-            status_code=400,
-            detail=messages.failtogettoken
+            status_code=404,
+            detail=messages.Messages.not_found('token')
         )
 
     token_data = response.json()
@@ -154,26 +154,26 @@ def verify_token(token: str):
         )
         return decoded
     except jwt.ExpiredSignatureError:
-        raise HTTPException(status_code=401, detail=messages.tokenexipired)
+        raise HTTPException(status_code=401, detail=messages.Messages.tokenexipired)
     except jwt.InvalidTokenError:
-        raise HTTPException(status_code=401, detail=messages.invalidtoken)
+        raise HTTPException(status_code=401, detail=messages.Messages.invalidtoken)
 
 
 def get_current_user(request: Request, session: Session = Depends(get_session)):
     access_token = request.cookies.get('access_token')
     if not access_token:
-        raise HTTPException(status_code=401, detail=messages.notauthenticated)
+        raise HTTPException(status_code=401, detail=messages.Messages.notauthenticated)
     payload = verify_token(access_token)
     if not payload:
         raise HTTPException(status_code=401, detail='aze')
     email = payload.get('email')
 
     if not email:
-        raise HTTPException(status_code=401, detail=messages.notauthenticated)
+        raise HTTPException(status_code=401, detail=messages.Messages.notauthenticated)
 
     user = session.exec(select(User).where(User.email == email)).first()
     if not user:
-        raise HTTPException(status_code=401, detail=messages.usernotfound)
+        raise HTTPException(status_code=401, detail=messages.Messages.not_found('user'))
     return user
 
 @router.post('/refresh')
@@ -191,8 +191,8 @@ def refresh_token(refresh_token: Annotated[str | None, Cookie()] = None):
     result = requests.post(TOKEN_URL, data=data, headers=headers)
     if result.status_code != 200:
         raise HTTPException(
-            status_code=400,
-            detail=messages.failtogettoken
+            status_code=404,
+            detail=messages.Messages.not_found('token')
         )
 
     token_data = result.json()
diff --git a/backend/src/contracts/contracts.py b/backend/src/contracts/contracts.py
index 3322c84..2d3082c 100644
--- a/backend/src/contracts/contracts.py
+++ b/backend/src/contracts/contracts.py
@@ -81,8 +81,6 @@ async def create_contract(
     recurrent_price = compute_recurrent_prices(recurrents, len(new_contract.form.shipments))
     price = recurrent_price + compute_occasional_prices(occasionals)
     cheques = list(map(lambda x: {"name": x.name, "value": x.value}, new_contract.cheques))
-    # TODO: send contract to referer
-
     try:
         pdf_bytes = generate_html_contract(
             new_contract,
@@ -165,10 +163,10 @@ def get_contract_file(
     user: models.User = Depends(get_current_user)
 ):
     if not service.is_allowed(session, user, id):
-        raise HTTPException(status_code=403, detail=messages.notallowed)
+        raise HTTPException(status_code=403, detail=messages.Messages.not_allowed('contract', 'get'))
     contract = service.get_one(session, id)
     if contract is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('contract'))
     filename = f'{contract.form.name.replace(' ', '_')}_{contract.form.season}_{contract.firstname}-{contract.lastname}'
     return StreamingResponse(
         io.BytesIO(contract.file),
@@ -185,7 +183,7 @@ def get_contract_files(
     user: models.User = Depends(get_current_user)
 ):
     if not form_service.is_allowed(session, user, form_id):
-        raise HTTPException(status_code=403, detail=messages.notallowed)
+        raise HTTPException(status_code=403, detail=messages.Messages.not_allowed('contracts', 'get'))
     form = form_service.get_one(session, form_id=form_id)
     contracts = service.get_all(session, user, forms=[form.name])
     zipped_contracts = io.BytesIO()
@@ -210,7 +208,7 @@ def get_contract_recap(
     user: models.User = Depends(get_current_user)
 ):
     if not form_service.is_allowed(session, user, form_id):
-        raise HTTPException(status_code=403, detail=messages.notallowed)
+        raise HTTPException(status_code=403, detail=messages.Messages.not_allowed('contract recap', 'get'))
     form = form_service.get_one(session, form_id=form_id)
     contracts = service.get_all(session, user, forms=[form.name])
     
@@ -225,17 +223,17 @@ def get_contract_recap(
 @router.get('/{id}', response_model=models.ContractPublic)
 def get_contract(id: int, session: Session = Depends(get_session), user: models.User = Depends(get_current_user)):
     if not service.is_allowed(session, user, id):
-        raise HTTPException(status_code=403, detail=messages.notallowed)
+        raise HTTPException(status_code=403, detail=messages.Messages.not_allowed('contract', 'get'))
     result = service.get_one(session, id)
     if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('contract'))
     return result
 
 @router.delete('/{id}', response_model=models.ContractPublic)
 def delete_contract(id: int, session: Session = Depends(get_session), user: models.User = Depends(get_current_user)):
     if not service.is_allowed(session, user, id):
-        raise HTTPException(status_code=403, detail=messages.notallowed)
+        raise HTTPException(status_code=403, detail=messages.Messages.not_allowed('contract', 'delete'))
     result = service.delete_one(session, id)
     if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('contract'))
     return result
diff --git a/backend/src/forms/forms.py b/backend/src/forms/forms.py
index b7f78f6..836b863 100644
--- a/backend/src/forms/forms.py
+++ b/backend/src/forms/forms.py
@@ -32,7 +32,7 @@ async def get_forms_filtered(
 async def get_form(id: int, session: Session = Depends(get_session)):
     result = service.get_one(session, id)
     if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('form'))
     return result
 
 @router.post('', response_model=models.FormPublic)
@@ -43,12 +43,12 @@ async def create_form(
 ):
     try:
         form = service.create_one(session, form)
-    except exceptions.ProductorNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.productornotfound)
-    except exceptions.UserNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.usernotfound)
-    except exceptions.FormCreateError:
-        raise HTTPException(status_code=400, detail=messages.forminputinvalid)
+    except exceptions.ProductorNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
+    except exceptions.UserNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
+    except exceptions.FormCreateError as error:
+        raise HTTPException(status_code=400, detail=str(error))
     return form
 
 @router.put('/{id}', response_model=models.FormPublic)
@@ -59,12 +59,12 @@ async def update_form(
 ):
     try:
         result = service.update_one(session, id, form)
-    except exceptions.FormNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.notfound)
-    except exceptions.ProductorNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.productornotfound)
-    except exceptions.UserNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.usernotfound)
+    except exceptions.FormNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
+    except exceptions.ProductorNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
+    except exceptions.UserNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
     return result
 
 @router.delete('/{id}', response_model=models.FormPublic)
@@ -75,6 +75,6 @@ async def delete_form(
 ):
     try:
         result = service.delete_one(session, id)
-    except exceptions.FormNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+    except exceptions.FormNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
     return result
diff --git a/backend/src/forms/service.py b/backend/src/forms/service.py
index 205a2a6..0342508 100644
--- a/backend/src/forms/service.py
+++ b/backend/src/forms/service.py
@@ -3,6 +3,7 @@ from sqlalchemy import func
 
 import src.models as models
 import src.forms.exceptions as exceptions
+import src.messages as messages
 
 def get_all(
     session: Session, 
@@ -49,11 +50,11 @@ def get_one(session: Session, form_id: int) -> models.FormPublic:
 
 def create_one(session: Session, form: models.FormCreate) -> models.FormPublic:
     if not form:
-        raise exceptions.FormCreateError('FormCreate input cannot be None')
+        raise exceptions.FormCreateError(messages.Messages.invalid_input('form', 'input cannot be None'))
     if not session.get(models.Productor, form.productor_id):
-        raise exceptions.ProductorNotFoundError(f'Productor {form.productor_id} not found')
+        raise exceptions.ProductorNotFoundError(messages.Messages.not_found('productor'))
     if not session.get(models.User, form.referer_id):
-        raise exceptions.UserNotFoundError(f'User {form.referer_id} not found')
+        raise exceptions.UserNotFoundError(messages.Messages.not_found('user'))
     form_create = form.model_dump(exclude_unset=True)
     new_form = models.Form(**form_create)
     session.add(new_form)
@@ -66,11 +67,11 @@ def update_one(session: Session, id: int, form: models.FormUpdate) -> models.For
     result = session.exec(statement)
     new_form = result.first()
     if not new_form:
-        raise exceptions.FormNotFoundError(f'Form {id} not found')
+        raise exceptions.FormNotFoundError(messages.Messages.not_found('form'))
     if form.productor_id and not session.get(models.Productor, form.productor_id):
-        raise exceptions.ProductorNotFoundError(f'Productor {form.productor_id} not found')
+        raise exceptions.ProductorNotFoundError(messages.Messages.not_found('productor'))
     if form.referer_id and not session.get(models.User, form.referer_id):
-        raise exceptions.UserNotFoundError(f'User {form.referer_id} not found')
+        raise exceptions.UserNotFoundError(messages.Messages.not_found('user'))
     form_updates = form.model_dump(exclude_unset=True)
     for key, value in form_updates.items():
         setattr(new_form, key, value)
@@ -84,7 +85,7 @@ def delete_one(session: Session, id: int) -> models.FormPublic:
     result = session.exec(statement)
     form = result.first()
     if not form:
-        raise exceptions.FormNotFoundError(f'Form {id} not found')
+        raise exceptions.FormNotFoundError(messages.Messages.not_found('form'))
     result = models.FormPublic.model_validate(form)
     session.delete(form)
     session.commit()
diff --git a/backend/src/messages.py b/backend/src/messages.py
index 318960d..790cda7 100644
--- a/backend/src/messages.py
+++ b/backend/src/messages.py
@@ -1,21 +1,19 @@
 pdferror = 'An error occured during PDF generation please contact administrator'
 
-tokenexipired = 'Token expired'
-invalidtoken = 'Invalid token'
-notauthenticated = 'Not authenticated'
-failtogettoken = 'Failed to get token'
-unauthorized = 'Unauthorized'
-notallowed = 'Not Allowed'
+class Messages:
+    unauthorized = 'User is Unauthorized'
+    notauthenticated = 'User is not authenticated'
+    tokenexipired = 'Token has expired'
+    invalidtoken = 'Token is invalid'
+    
+    @staticmethod
+    def not_found(resource: str) -> str:
+        return f'{resource.capitalize()} not found'
+    
+    @staticmethod
+    def invalid_input(resource: str, reason: str = "") -> str:
+        return f'Invalid {resource} input {':' if reason else ""} {reason}'
 
-notfound = 'Resource was not found.'
-usernotfound = 'User not found'
-userloggedout = 'User logged out'
-
-productorinputinvalid = 'Invalid productor input'
-productornotfound = 'Productor not found'
-
-forminputinvalid = 'Invalid form input'
-formnotfound = 'Form not found'
-
-productinputinvalid = 'Invalid product input'
-productnotfound = 'Product not found'
+    @staticmethod
+    def not_allowed(resource: str, action: str) -> str:
+        return f'User is not allowed to {action} this {resource}'    
\ No newline at end of file
diff --git a/backend/src/models.py b/backend/src/models.py
index fa25ee4..dcc407b 100644
--- a/backend/src/models.py
+++ b/backend/src/models.py
@@ -303,7 +303,7 @@ class Shipment(ShipmentBase, table=True):
 
 class ShipmentUpdate(SQLModel):
     name: str | None
-    date: str | None
+    date: datetime.date | None
     product_ids: list[int] | None = []
 
 class ShipmentCreate(ShipmentBase):
diff --git a/backend/src/productors/productors.py b/backend/src/productors/productors.py
index a6ec468..2dd390b 100644
--- a/backend/src/productors/productors.py
+++ b/backend/src/productors/productors.py
@@ -26,7 +26,7 @@ def get_productor(
 ):
     result = service.get_one(session, id)
     if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('productor'))
     return result
 
 @router.post('', response_model=models.ProductorPublic)
@@ -37,8 +37,8 @@ def create_productor(
 ):
     try:
         result = service.create_one(session, productor)
-    except exceptions.ProductorCreateError:
-        raise HTTPException(status_code=400, detail=messages.productorinputinvalid)
+    except exceptions.ProductorCreateError as error:
+        raise HTTPException(status_code=400, detail=str(error))
     return result
 
 @router.put('/{id}', response_model=models.ProductorPublic)
@@ -49,8 +49,8 @@ def update_productor(
 ):
     try:
         result = service.update_one(session, id, productor)
-    except exceptions.ProductorNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.productornotfound)
+    except exceptions.ProductorNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
     return result
 
 @router.delete('/{id}', response_model=models.ProductorPublic)
@@ -61,6 +61,6 @@ def delete_productor(
 ):
     try:
         result = service.delete_one(session, id)
-    except exceptions.ProductorNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.productornotfound)
+    except exceptions.ProductorNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
     return result
diff --git a/backend/src/productors/service.py b/backend/src/productors/service.py
index ae26b2b..2580573 100644
--- a/backend/src/productors/service.py
+++ b/backend/src/productors/service.py
@@ -1,6 +1,7 @@
 from sqlmodel import Session, select
 import src.models as models
 import src.productors.exceptions as exceptions
+import src.messages as messages
 
 def get_all(
     session: Session,
@@ -22,7 +23,7 @@ def get_one(session: Session, productor_id: int) -> models.ProductorPublic:
 
 def create_one(session: Session, productor: models.ProductorCreate) -> models.ProductorPublic:
     if not productor:
-        raise exceptions.ProductorCreateError('ProductorCreate input cannot be None')
+        raise exceptions.ProductorCreateError(messages.Messages.invalid_input('productor', 'input cannot be None'))
     productor_create = productor.model_dump(exclude_unset=True, exclude='payment_methods')
     new_productor = models.Productor(**productor_create)
 
@@ -43,7 +44,7 @@ def update_one(session: Session, id: int, productor: models.ProductorUpdate) ->
     result = session.exec(statement)
     new_productor = result.first()
     if not new_productor:
-        raise exceptions.ProductorNotFoundError(f'Productor {id} not found')
+        raise exceptions.ProductorNotFoundError(messages.Messages.not_found('productor'))
     
     productor_updates = productor.model_dump(exclude_unset=True)
     if 'payment_methods' in productor_updates:
@@ -71,7 +72,7 @@ def delete_one(session: Session, id: int) -> models.ProductorPublic:
     result = session.exec(statement)
     productor = result.first()
     if not productor:
-        raise exceptions.ProductorNotFoundError(f'Productor {id} not found')
+        raise exceptions.ProductorNotFoundError(messages.Messages.not_found('productor'))
     result = models.ProductorPublic.model_validate(productor)
     session.delete(productor)
     session.commit()
diff --git a/backend/src/products/products.py b/backend/src/products/products.py
index 47e3245..afb7988 100644
--- a/backend/src/products/products.py
+++ b/backend/src/products/products.py
@@ -33,7 +33,7 @@ def get_product(
 ):
     result = service.get_one(session, id)
     if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('product'))
     return result
 
 @router.post('', response_model=models.ProductPublic)
@@ -44,10 +44,10 @@ def create_product(
 ):
     try:
         result = service.create_one(session, product)
-    except exceptions.ProductCreateError:
-        raise HTTPException(status_code=400, detail=messages.productinputinvalid)
-    except exceptions.ProductorNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.productornotfound)
+    except exceptions.ProductCreateError as error:
+        raise HTTPException(status_code=400, detail=str(error))
+    except exceptions.ProductorNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
     return result
 
 @router.put('/{id}', response_model=models.ProductPublic)
@@ -58,10 +58,10 @@ def update_product(
 ):
     try:
         result = service.update_one(session, id, product)
-    except exceptions.ProductNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.productnotfound)
-    except exceptions.ProductorNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.productornotfound)
+    except exceptions.ProductNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
+    except exceptions.ProductorNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
     return result
 
 @router.delete('/{id}', response_model=models.ProductPublic)
@@ -72,6 +72,6 @@ def delete_product(
 ):
     try:
         result = service.delete_one(session, id)
-    except exceptions.ProductNotFoundError:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+    except exceptions.ProductNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
     return result
diff --git a/backend/src/products/service.py b/backend/src/products/service.py
index a276355..fc200e8 100644
--- a/backend/src/products/service.py
+++ b/backend/src/products/service.py
@@ -1,6 +1,7 @@
 from sqlmodel import Session, select
 import src.models as models
 import src.products.exceptions as exceptions
+import src.messages as messages
 
 def get_all(
     session: Session, 
@@ -26,9 +27,9 @@ def get_one(session: Session, product_id: int) -> models.ProductPublic:
 
 def create_one(session: Session, product: models.ProductCreate) -> models.ProductPublic:
     if not product:
-        raise exceptions.ProductCreateError('ProductCreate input cannot be None')
+        raise exceptions.ProductCreateError(messages.Messages.invalid_input('product', 'input cannot be None'))
     if not session.get(models.Productor, product.productor_id):
-        raise exceptions.ProductorNotFoundError(f'Productor {product.productor_id} not found')
+        raise exceptions.ProductorNotFoundError(messages.Messages.not_found('productor'))
     product_create = product.model_dump(exclude_unset=True)
     new_product = models.Product(**product_create)
     session.add(new_product)
@@ -41,9 +42,9 @@ def update_one(session: Session, id: int, product: models.ProductUpdate) -> mode
     result = session.exec(statement)
     new_product = result.first()
     if not new_product:
-        raise exceptions.ProductNotFoundError(f'Product {id} not found')
+        raise exceptions.ProductNotFoundError(messages.Messages.not_found('product'))
     if product.productor_id and not session.get(models.Productor, product.productor_id):
-        raise exceptions.ProductorNotFoundError(f'Productor {product.productor_id} not found')
+        raise exceptions.ProductorNotFoundError(messages.Messages.not_found('productor'))
 
     product_updates = product.model_dump(exclude_unset=True)
     for key, value in product_updates.items():
@@ -59,7 +60,7 @@ def delete_one(session: Session, id: int) -> models.ProductPublic:
     result = session.exec(statement)
     product = result.first()
     if not product:
-        raise exceptions.ProductNotFoundError(f'Product {id} not found')
+        raise exceptions.ProductNotFoundError(messages.Messages.not_found('product'))
     result = models.ProductPublic.model_validate(product)
     session.delete(product)
     session.commit()
diff --git a/backend/src/shipments/exceptions.py b/backend/src/shipments/exceptions.py
new file mode 100644
index 0000000..39cf869
--- /dev/null
+++ b/backend/src/shipments/exceptions.py
@@ -0,0 +1,11 @@
+class ShipmentServiceError(Exception):
+    def __init__(self, message: str):
+        super().__init__(message)
+
+class ShipmentNotFoundError(ShipmentServiceError):
+    pass
+
+class ShipmentCreateError(ShipmentServiceError):
+    def __init__(self, message: str, field: str | None = None):
+        super().__init__(message)
+        self.field = field
\ No newline at end of file
diff --git a/backend/src/shipments/service.py b/backend/src/shipments/service.py
index 5158fd4..8d71413 100644
--- a/backend/src/shipments/service.py
+++ b/backend/src/shipments/service.py
@@ -1,12 +1,15 @@
 from sqlmodel import Session, select
 import src.models as models
+import src.shipments.exceptions as exceptions
+import src.messages as messages
+import datetime
 
 def get_all(
     session: Session,
     user: models.User,
     names: list[str],
     dates: list[str],
-    forms: list[int]
+    forms: list[str]
 ) -> list[models.ShipmentPublic]:
     statement = select(models.Shipment)\
         .join(models.Form, models.Shipment.form_id == models.Form.id)\
@@ -16,15 +19,17 @@ def get_all(
     if len(names) > 0:
         statement = statement.where(models.Shipment.name.in_(names))
     if len(dates) > 0:
-        statement = statement.where(models.Shipment.date.in_(list(map(lambda x: datetime.strptime(x, '%Y-%m-%d'), dates))))
+        statement = statement.where(models.Shipment.date.in_(list(map(lambda x: datetime.datetime.strptime(x, '%Y-%m-%d').date(), dates))))
     if len(forms) > 0:
-        statement = statement.join(models.Form).where(models.Form.name.in_(forms))
+        statement = statement.where(models.Form.name.in_(forms))
     return session.exec(statement.order_by(models.Shipment.name)).all()
 
 def get_one(session: Session, shipment_id: int) -> models.ShipmentPublic:
     return session.get(models.Shipment, shipment_id)
 
 def create_one(session: Session, shipment: models.ShipmentCreate) -> models.ShipmentPublic:
+    if shipment is None:
+        raise exceptions.ShipmentCreateError(messages.Messages.invalid_input('shipment', 'input cannot be None'))
     products = session.exec(select(models.Product).where(models.Product.id.in_(shipment.product_ids))).all()
     shipment_create = shipment.model_dump(exclude_unset=True, exclude={'product_ids'})
     new_shipment = models.Shipment(**shipment_create, products=products)
@@ -34,11 +39,13 @@ def create_one(session: Session, shipment: models.ShipmentCreate) -> models.Ship
     return new_shipment
 
 def update_one(session: Session, id: int, shipment: models.ShipmentUpdate) -> models.ShipmentPublic:
+    if shipment is None:
+        raise exceptions.ShipmentCreateError(messages.Messages.invalid_input('shipment', 'input cannot be None'))
     statement = select(models.Shipment).where(models.Shipment.id == id)
     result = session.exec(statement)
     new_shipment = result.first()
     if not new_shipment:
-        return None
+        raise exceptions.ShipmentNotFoundError(messages.Messages.not_found('shipment'))
 
     products_to_add = session.exec(select(models.Product).where(models.Product.id.in_(shipment.product_ids))).all()
     new_shipment.products.clear()
@@ -59,7 +66,8 @@ def delete_one(session: Session, id: int) -> models.ShipmentPublic:
     result = session.exec(statement)
     shipment = result.first()
     if not shipment:
-        return None
+        raise exceptions.ShipmentNotFoundError(messages.Messages.not_found('shipment'))
+
     result = models.ShipmentPublic.model_validate(shipment)
     session.delete(shipment)
     session.commit()
diff --git a/backend/src/shipments/shipments.py b/backend/src/shipments/shipments.py
index 3a4c85d..f969d02 100644
--- a/backend/src/shipments/shipments.py
+++ b/backend/src/shipments/shipments.py
@@ -4,6 +4,7 @@ import src.models as models
 from src.database import get_session
 from sqlmodel import Session
 import src.shipments.service as service
+import src.shipments.exceptions as exceptions
 from src.auth.auth import get_current_user
 
 router = APIRouter(prefix='/shipments')
@@ -32,7 +33,7 @@ def get_shipment(
 ):
     result = service.get_one(session, id)
     if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('shipment'))
     return result
 
 @router.post('', response_model=models.ShipmentPublic)
@@ -41,17 +42,23 @@ def create_shipment(
     user: models.User = Depends(get_current_user),
     session: Session = Depends(get_session)
 ):
-    return service.create_one(session, shipment)
+    try:
+        result = service.create_one(session, shipment)
+    except exceptions.ShipmentCreateError as error:
+        raise HTTPException(status_code=400, detail=str(error))
+    return result
 
 @router.put('/{id}', response_model=models.ShipmentPublic)
 def update_shipment(
-    id: int, shipment: models.ShipmentUpdate,
+    id: int, 
+    shipment: models.ShipmentUpdate,
     user: models.User = Depends(get_current_user),
     session: Session = Depends(get_session)
 ):
-    result = service.update_one(session, id, shipment)
-    if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+    try:
+        result = service.update_one(session, id, shipment)
+    except exceptions.ShipmentNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
     return result
 
 @router.delete('/{id}', response_model=models.ShipmentPublic)
@@ -60,7 +67,8 @@ def delete_shipment(
     user: models.User = Depends(get_current_user),
     session: Session = Depends(get_session)
 ):
-    result = service.delete_one(session, id)
-    if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+    try:
+        result = service.delete_one(session, id)
+    except exceptions.ShipmentNotFoundError as error:
+        raise HTTPException(status_code=404, detail=str(error))
     return result
diff --git a/backend/src/templates/templates.py b/backend/src/templates/templates.py
index 2f33222..e5c471e 100644
--- a/backend/src/templates/templates.py
+++ b/backend/src/templates/templates.py
@@ -23,7 +23,7 @@ def get_template(
 ):
     result = service.get_one(session, id)
     if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('template'))
     return result
 
 @router.post('', response_model=models.TemplatePublic)
@@ -42,7 +42,7 @@ def update_template(
 ):
     result = service.update_one(session, id, template)
     if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('template'))
     return result
 
 @router.delete('/{id}', response_model=models.TemplatePublic)
@@ -53,5 +53,5 @@ def delete_template(
 ):
     result = service.delete_one(session, id)
     if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('template'))
     return result
diff --git a/backend/src/users/exceptions.py b/backend/src/users/exceptions.py
new file mode 100644
index 0000000..771bd04
--- /dev/null
+++ b/backend/src/users/exceptions.py
@@ -0,0 +1,11 @@
+class UserServiceError(Exception):
+    def __init__(self, message: str):
+        super().__init__(message)
+
+class UserNotFoundError(UserServiceError):
+    pass
+
+class UserCreateError(UserServiceError):
+    def __init__(self, message: str, field: str | None = None):
+        super().__init__(message)
+        self.field = field
\ No newline at end of file
diff --git a/backend/src/users/service.py b/backend/src/users/service.py
index 1ceb8d5..466417f 100644
--- a/backend/src/users/service.py
+++ b/backend/src/users/service.py
@@ -1,5 +1,9 @@
 from sqlmodel import Session, select
+
 import src.models as models
+import src.messages as messages
+
+import src.users.exceptions as exceptions
 
 def get_all(
     session: Session,
@@ -49,6 +53,8 @@ def get_roles(session: Session):
     return session.exec(statement.order_by(models.ContractType.name)).all()
 
 def create_one(session: Session, user: models.UserCreate) -> models.UserPublic:
+    if user is None:
+        raise exceptions.UserCreateError(messages.Messages.invalid_input('user', 'input cannot be None'))
     new_user = models.User(
         name=user.name,
         email=user.email
@@ -63,12 +69,13 @@ def create_one(session: Session, user: models.UserCreate) -> models.UserPublic:
     return new_user
 
 def update_one(session: Session, id: int, user: models.UserCreate) -> models.UserPublic:
+    if user is None:
+        raise exceptions.UserCreateError(messages.s.invalid_input('user', 'input cannot be None'))
     statement = select(models.User).where(models.User.id == id)
     result = session.exec(statement)
     new_user = result.first()
     if not new_user:
-        return None
-
+        raise exceptions.UserNotFoundError(f'User {id} not found')
     new_user.email = user.email
     new_user.name = user.name
 
@@ -84,7 +91,7 @@ def delete_one(session: Session, id: int) -> models.UserPublic:
     result = session.exec(statement)
     user = result.first()
     if not user:
-        return None
+        raise exceptions.UserNotFoundError(f'User {id} not found')
     result = models.UserPublic.model_validate(user)
     session.delete(user)
     session.commit()
diff --git a/backend/src/users/users.py b/backend/src/users/users.py
index 8c375bd..73a303f 100644
--- a/backend/src/users/users.py
+++ b/backend/src/users/users.py
@@ -5,6 +5,7 @@ from src.database import get_session
 from sqlmodel import Session
 import src.users.service as service
 from src.auth.auth import get_current_user
+import src.users.exceptions as exceptions
 
 router = APIRouter(prefix='/users')
 
@@ -36,7 +37,7 @@ def get_users(
 ):
     result = service.get_one(session, id)
     if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('user'))
     return result
 
 @router.post('', response_model=models.UserPublic)
@@ -45,7 +46,11 @@ def create_user(
     logged_user: models.User = Depends(get_current_user),
     session: Session = Depends(get_session)
 ):
-    return service.create_one(session, user)
+    try:
+        user = service.create_one(session, user)
+    except exceptions.UserCreateError as error:
+        raise HTTPException(status_code=400, detail=str(error))
+    return user
 
 @router.put('/{id}', response_model=models.UserPublic)
 def update_user(
@@ -54,9 +59,10 @@ def update_user(
     logged_user: models.User = Depends(get_current_user),
     session: Session = Depends(get_session)
 ):
-    result = service.update_one(session, id, user)
-    if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+    try:
+        result = service.update_one(session, id, user)
+    except exceptions.UserNotFoundError as error:
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('user'))
     return result
 
 @router.delete('/{id}', response_model=models.UserPublic)
@@ -65,7 +71,8 @@ def delete_user(
     user: models.User = Depends(get_current_user),
     session: Session = Depends(get_session)
 ):
-    result = service.delete_one(session, id)
-    if result is None:
-        raise HTTPException(status_code=404, detail=messages.notfound)
+    try:
+        result = service.delete_one(session, id)
+    except exceptions.UserNotFoundError as error:
+        raise HTTPException(status_code=404, detail=messages.Messages.not_found('user'))
     return result
diff --git a/backend/tests/fixtures.py b/backend/tests/fixtures.py
index 1303789..6df8012 100644
--- a/backend/tests/fixtures.py
+++ b/backend/tests/fixtures.py
@@ -1,12 +1,15 @@
 import pytest
+import datetime
 from sqlmodel import Session
 
 import src.models as models
 import src.forms.service as forms_service
+import src.shipments.service as shipments_service
 import src.productors.service as productors_service
 import src.products.service as products_service
 import src.users.service as users_service
 import tests.factories.forms as forms_factory
+import tests.factories.shipments as shipments_factory
 import tests.factories.productors as productors_factory
 import tests.factories.products as products_factory
 import tests.factories.users as users_factory
@@ -77,6 +80,36 @@ def user(session: Session) -> models.UserPublic:
     )
     return user
 
+@pytest.fixture
+def users(session: Session) -> list[models.UserPublic]:
+    users = [
+        users_service.create_one(
+            session,
+            users_factory.user_create_factory(
+                name='test user 1 (admin)', 
+                email='test1@test.com',
+                role_names=['Légumineuses', 'Légumes', 'Oeufs', 'Porc-Agneau', 'Vin', 'Fruits']
+            )
+        ),
+        users_service.create_one(
+            session,
+            users_factory.user_create_factory(
+                name='test user 2', 
+                email='test2@test.com',
+                role_names=['Légumineuses']
+            )
+        ),
+        users_service.create_one(
+            session,
+            users_factory.user_create_factory(
+                name='test user 3', 
+                email='test3@test.com',
+                role_names=['Porc-Agneau']
+            )
+        )
+    ]
+    return users
+
 @pytest.fixture
 def referer(session: Session) -> models.UserPublic:
     referer = users_service.create_one(
@@ -89,6 +122,30 @@ def referer(session: Session) -> models.UserPublic:
     )
     return referer
 
+@pytest.fixture
+def shipments(session: Session, forms: list[models.FormPublic], products: list[models.ProductPublic]):
+    shipments = [
+        shipments_service.create_one(
+            session, 
+            shipments_factory.shipment_create_factory(
+                name='test shipment 1',
+                date=datetime.date(2025, 10, 10),
+                form_id=forms[0].id,
+                product_ids=[p.id for p in products]
+            )
+        ),
+        shipments_service.create_one(
+            session, 
+            shipments_factory.shipment_create_factory(
+                name='test shipment 2',
+                date=datetime.date(2025, 11, 10),
+                form_id=forms[0].id,
+                product_ids=[p.id for p in products]
+            )
+        ),
+    ]
+    return shipments
+
 @pytest.fixture
 def forms(
     session: Session, 
diff --git a/backend/tests/routers/test_contracts.py b/backend/tests/routers/test_contracts.py
index 7aec6dc..e71ea3d 100644
--- a/backend/tests/routers/test_contracts.py
+++ b/backend/tests/routers/test_contracts.py
@@ -122,6 +122,9 @@ class TestContracts:
 
         app.dependency_overrides.clear()
 
+    def test_create_one(self, client, mocker, mock_session, mock_user):
+        pass
+
     def test_delete_one(self, client, mocker, mock_session, mock_user):
         contract_result = contract_factory.contract_public_factory(name='test contract delete')
 
diff --git a/backend/tests/routers/test_forms.py b/backend/tests/routers/test_forms.py
index 4836aa4..f81de1d 100644
--- a/backend/tests/routers/test_forms.py
+++ b/backend/tests/routers/test_forms.py
@@ -5,6 +5,7 @@ from src.main import app
 from src.auth.auth import get_current_user
 import tests.factories.forms as form_factory
 from fastapi.exceptions import HTTPException
+import src.messages as messages
 
 class TestForms:
     def test_get_all(self, client, mocker, mock_session, mock_user):
@@ -123,6 +124,44 @@ class TestForms:
             mock_session,
             form_create
         )
+    
+    def test_create_one_referer_notfound(self, client, mocker, mock_session, mock_user):
+        form_body = form_factory.form_body_factory(name='test form create', referer_id=12312)
+        form_create = form_factory.form_create_factory(name='test form create', referer_id=12312)
+
+        mock = mocker.patch.object(
+            service,
+            'create_one',
+            side_effect=forms_exceptions.UserNotFoundError(messages.Messages.not_found('referer'))
+        )
+
+        response = client.post('/api/forms', json=form_body)
+        response_data = response.json()
+
+        assert response.status_code == 404
+        mock.assert_called_once_with(
+            mock_session,
+            form_create
+        )
+
+    def test_create_one_productor_notfound(self, client, mocker, mock_session, mock_user):
+        form_body = form_factory.form_body_factory(name='test form create', productor_id=1231)
+        form_create = form_factory.form_create_factory(name='test form create', productor_id=1231)
+
+        mock = mocker.patch.object(
+            service,
+            'create_one',
+            side_effect=forms_exceptions.ProductorNotFoundError(messages.Messages.not_found('productor'))
+        )
+
+        response = client.post('/api/forms', json=form_body)
+        response_data = response.json()
+
+        assert response.status_code == 404
+        mock.assert_called_once_with(
+            mock_session,
+            form_create
+        )
 
     def test_create_one_unauthorized(self, client, mocker, mock_session, mock_user):
         def unauthorized():
@@ -164,12 +203,51 @@ class TestForms:
     def test_update_one_notfound(self, client, mocker, mock_session, mock_user):
         form_body = form_factory.form_body_factory(name='test form update')
         form_update = form_factory.form_update_factory(name='test form update')
-        form_result = None
 
         mock = mocker.patch.object(
             service,
             'update_one',
-            side_effect=forms_exceptions.FormNotFoundError('Form 1 not found')
+            side_effect=forms_exceptions.FormNotFoundError(messages.Messages.not_found('form'))
+        )
+
+        response = client.put('/api/forms/2', json=form_body)
+        response_data = response.json()
+
+        assert response.status_code == 404
+        mock.assert_called_once_with(
+            mock_session,
+            2,
+            form_update
+        )
+    
+    def test_update_one_referer_notfound(self, client, mocker, mock_session, mock_user):
+        form_body = form_factory.form_body_factory(name='test form update')
+        form_update = form_factory.form_update_factory(name='test form update')
+
+        mock = mocker.patch.object(
+            service,
+            'update_one',
+            side_effect=forms_exceptions.UserNotFoundError(messages.Messages.not_found('referer'))
+        )
+
+        response = client.put('/api/forms/2', json=form_body)
+        response_data = response.json()
+
+        assert response.status_code == 404
+        mock.assert_called_once_with(
+            mock_session,
+            2,
+            form_update
+        )
+
+    def test_update_one_productor_notfound(self, client, mocker, mock_session, mock_user):
+        form_body = form_factory.form_body_factory(name='test form update')
+        form_update = form_factory.form_update_factory(name='test form update')
+
+        mock = mocker.patch.object(
+            service,
+            'update_one',
+            side_effect=forms_exceptions.ProductorNotFoundError(messages.Messages.not_found('productor'))
         )
 
         response = client.put('/api/forms/2', json=form_body)
@@ -222,7 +300,7 @@ class TestForms:
         mock = mocker.patch.object(
             service,
             'delete_one',
-            side_effect=forms_exceptions.FormNotFoundError('Form 2 not found')
+            side_effect=forms_exceptions.FormNotFoundError(messages.Messages.not_found('form'))
         )
 
         response = client.delete('/api/forms/2')
diff --git a/backend/tests/routers/test_productors.py b/backend/tests/routers/test_productors.py
index 4227823..83839a5 100644
--- a/backend/tests/routers/test_productors.py
+++ b/backend/tests/routers/test_productors.py
@@ -1,11 +1,14 @@
-import src.productors.service as service
-import src.models as models
+from fastapi.exceptions import HTTPException
+
 from src.main import app
+import src.models as models
+import src.messages as messages
 from src.auth.auth import get_current_user
-import tests.factories.productors as productor_factory
+
+import src.productors.service as service
 import src.productors.exceptions as exceptions
 
-from fastapi.exceptions import HTTPException
+import tests.factories.productors as productor_factory
 
 class TestProductors:
     def test_get_all(self, client, mocker, mock_session, mock_user):
@@ -181,7 +184,7 @@ class TestProductors:
         mock = mocker.patch.object(
             service,
             'update_one',
-            side_effect=exceptions.ProductorNotFoundError('Productor 1 not found')
+            side_effect=exceptions.ProductorNotFoundError(messages.Messages.not_found('productor'))
         )
 
         response = client.put('/api/productors/2', json=productor_body)
@@ -234,7 +237,7 @@ class TestProductors:
         mock = mocker.patch.object(
             service,
             'delete_one',
-            side_effect=exceptions.ProductorNotFoundError('Productor 1 not found')
+            side_effect=exceptions.ProductorNotFoundError(messages.Messages.not_found('productor'))
         )
 
         response = client.delete('/api/productors/2')
diff --git a/backend/tests/routers/test_shipments.py b/backend/tests/routers/test_shipments.py
index 49a3810..3313c91 100644
--- a/backend/tests/routers/test_shipments.py
+++ b/backend/tests/routers/test_shipments.py
@@ -1,6 +1,8 @@
 import src.shipments.service as service
 import src.models as models
 from src.main import app
+import src.messages as messages
+import src.shipments.exceptions as exceptions
 from src.auth.auth import get_current_user
 import tests.factories.shipments as shipment_factory
 
@@ -177,12 +179,11 @@ class TestShipments:
     def test_update_one_notfound(self, client, mocker, mock_session, mock_user):
         shipment_body = shipment_factory.shipment_body_factory(name='test shipment update')
         shipment_update = shipment_factory.shipment_update_factory(name='test shipment update')
-        shipment_result = None
 
         mock = mocker.patch.object(
             service,
             'update_one',
-            return_value=shipment_result
+            side_effect=exceptions.ShipmentNotFoundError(messages.Messages.not_found('shipment'))
         )
 
         response = client.put('/api/shipments/2', json=shipment_body)
@@ -235,7 +236,7 @@ class TestShipments:
         mock = mocker.patch.object(
             service,
             'delete_one',
-            return_value=shipment_result
+            side_effect=exceptions.ShipmentNotFoundError(messages.Messages.not_found('shipment'))
         )
 
         response = client.delete('/api/shipments/2')
diff --git a/backend/tests/routers/test_users.py b/backend/tests/routers/test_users.py
index 9409b28..80e32eb 100644
--- a/backend/tests/routers/test_users.py
+++ b/backend/tests/routers/test_users.py
@@ -3,6 +3,7 @@ import src.models as models
 from src.main import app
 from src.auth.auth import get_current_user
 import tests.factories.users as user_factory
+import src.users.exceptions as exceptions
 
 from fastapi.exceptions import HTTPException
 
@@ -178,7 +179,7 @@ class TestUsers:
         mock = mocker.patch.object(
             service,
             'update_one',
-            return_value=user_result
+            side_effect=exceptions.UserNotFoundError('User 2 not found')
         )
 
         response = client.put('/api/users/2', json=user_body)
@@ -231,7 +232,7 @@ class TestUsers:
         mock = mocker.patch.object(
             service,
             'delete_one',
-            return_value=user_result
+            side_effect=exceptions.UserNotFoundError('User 2 not found')
         )
 
         response = client.delete('/api/users/2')
diff --git a/backend/tests/services/test_shipments_service.py b/backend/tests/services/test_shipments_service.py
new file mode 100644
index 0000000..458ace7
--- /dev/null
+++ b/backend/tests/services/test_shipments_service.py
@@ -0,0 +1,143 @@
+import pytest
+import datetime
+from sqlmodel import Session
+
+import src.models as models
+import src.shipments.service as shipments_service
+import src.shipments.exceptions as shipments_exceptions
+import tests.factories.shipments as shipments_factory
+
+class TestShipmentsService:
+    def test_get_all_shipments(
+        self, 
+        session: Session, 
+        shipments: list[models.ShipmentPublic],
+        user: models.UserPublic,
+    ):
+        result = shipments_service.get_all(session, user, [], [], [])
+
+        assert len(result) == 2
+        assert result == shipments
+
+    def test_get_all_shipments_filter_names(
+        self, 
+        session: Session, 
+        shipments: list[models.ShipmentPublic],
+        user: models.UserPublic,
+    ):
+        result = shipments_service.get_all(session, user, ['test shipment 1'], [], [])
+
+        assert len(result) == 1
+        assert result == [shipments[0]]
+
+    def test_get_all_shipments_filter_dates(
+        self, 
+        session: Session, 
+        shipments: list[models.ShipmentPublic],
+        user: models.UserPublic,
+    ):
+        result = shipments_service.get_all(session, user, [], ['2025-10-10'], [])
+
+        assert len(result) == 1
+    
+    def test_get_all_shipments_filter_forms(
+        self, 
+        session: Session, 
+        shipments: list[models.ShipmentPublic],
+        forms: list[models.FormPublic],
+        user: models.UserPublic,
+    ):
+        result = shipments_service.get_all(session, user, [], [], [forms[0].name])
+
+        assert len(result) == 2
+
+    def test_get_all_shipments_all_filters(
+        self, 
+        session: Session, 
+        shipments: list[models.ShipmentPublic],
+        forms: list[models.FormPublic],
+        user: models.UserPublic,
+    ):
+        result = shipments_service.get_all(session, user, ['test shipment 1'], ['2025-10-10'], [forms[0].name])
+
+        assert len(result) == 1
+
+    def test_get_one_shipment(self, session: Session, shipments: list[models.ShipmentPublic]):
+        result = shipments_service.get_one(session, shipments[0].id)
+
+        assert result == shipments[0]
+
+    def test_get_one_shipment_notfound(self, session: Session):
+        result = shipments_service.get_one(session, 122)
+
+        assert result == None
+    
+    def test_create_shipment(
+        self, 
+        session: Session,
+    ):
+        shipment_create = shipments_factory.shipment_create_factory(
+            name='new test shipment',
+            date='2025-10-10',
+        )
+        result = shipments_service.create_one(session, shipment_create)
+
+        assert result.id is not None
+        assert result.name == "new test shipment"
+    
+    def test_create_shipment_invalidinput(
+        self, 
+        session: Session, 
+    ):
+        shipment_create = None
+        with pytest.raises(shipments_exceptions.ShipmentCreateError):
+            result = shipments_service.create_one(session, shipment_create)
+
+    def test_update_shipment(
+        self, 
+        session: Session,
+        shipments: list[models.ShipmentPublic]
+    ):
+        shipment_update = shipments_factory.shipment_update_factory(
+            name='updated shipment 1',
+            date='2025-12-10',
+        )
+        shipment_id = shipments[0].id
+        result = shipments_service.update_one(session, shipment_id, shipment_update)
+
+        assert result.id == shipment_id
+        assert result.name == 'updated shipment 1'
+        assert result.date == datetime.date(2025, 12, 10)
+    
+    def test_update_shipment_notfound(
+        self, 
+        session: Session,
+    ):
+        shipment_update = shipments_factory.shipment_update_factory(
+            name='updated shipment 1',
+            date=datetime.date(2025, 10, 10),
+        )
+        shipment_id = 123
+        with pytest.raises(shipments_exceptions.ShipmentNotFoundError):
+            result = shipments_service.update_one(session, shipment_id, shipment_update)
+    
+    def test_delete_shipment(
+        self, 
+        session: Session, 
+        shipments: list[models.ShipmentPublic]
+    ):
+        shipment_id = shipments[0].id
+        result = shipments_service.delete_one(session, shipment_id)
+
+        check = shipments_service.get_one(session, shipment_id)
+        assert check == None
+    
+    def test_delete_shipment_notfound(
+        self, 
+        session: Session, 
+        shipments: list[models.ShipmentPublic]
+    ):
+        shipment_id = 123
+        with pytest.raises(shipments_exceptions.ShipmentNotFoundError):
+            result = shipments_service.delete_one(session, shipment_id)
+
diff --git a/backend/tests/services/test_users_service.py b/backend/tests/services/test_users_service.py
new file mode 100644
index 0000000..1c398d8
--- /dev/null
+++ b/backend/tests/services/test_users_service.py
@@ -0,0 +1,115 @@
+import pytest
+from sqlmodel import Session
+
+import src.models as models
+import src.users.service as users_service
+import src.users.exceptions as users_exceptions
+import tests.factories.users as users_factory
+
+class TestUsersService:
+    def test_get_all_users(self, session: Session, users: list[models.UserPublic]):
+        result = users_service.get_all(session, [], [])
+
+        assert len(result) == 3
+        assert result == users
+
+    def test_get_all_users_filter_names(self, session: Session, users: list[models.UserPublic]):
+        result = users_service.get_all(session, ['test user 1 (admin)'], [])
+
+        assert len(result) == 1
+        assert result == [users[0]]
+
+    def test_get_all_users_filter_emails(self, session: Session, users: list[models.UserPublic]):
+        result = users_service.get_all(session, [], ['test1@test.com'])
+
+        assert len(result) == 1
+
+    def test_get_all_users_all_filters(self, session: Session, users: list[models.UserPublic]):
+        result = users_service.get_all(session, ['test user 1 (admin)'], ['test1@test.com'])
+
+        assert len(result) == 1
+
+    def test_get_one_user(self, session: Session, users: list[models.UserPublic]):
+        result = users_service.get_one(session, users[0].id)
+
+        assert result == users[0]
+
+    def test_get_one_user_notfound(self, session: Session):
+        result = users_service.get_one(session, 122)
+
+        assert result == None
+    
+    def test_create_user(
+        self, 
+        session: Session,
+    ):
+        user_create = users_factory.user_create_factory(
+            name="new test user",
+            email='test@test.fr',
+            role_names=['test role']
+        )
+        result = users_service.create_one(session, user_create)
+
+        assert result.id is not None
+        assert result.name == "new test user"
+        assert result.email == "test@test.fr"
+        assert len(result.roles) == 1
+    
+    def test_create_user_invalidinput(
+        self, 
+        session: Session, 
+    ):
+        user_create = None
+        with pytest.raises(users_exceptions.UserCreateError):
+            result = users_service.create_one(session, user_create)
+
+    def test_update_user(
+        self, 
+        session: Session,
+        users: list[models.UserPublic]
+    ):
+        user_update = users_factory.user_update_factory(
+            name="updated test user",
+            email='test@testttt.fr',
+            role_names=['test role']
+        )
+        user_id = users[0].id
+        result = users_service.update_one(session, user_id, user_update)
+
+        assert result.id == user_id
+        assert result.name == 'updated test user'
+        assert result.email == 'test@testttt.fr'
+    
+    def test_update_user_notfound(
+        self, 
+        session: Session,
+    ):
+        user_update = users_factory.user_update_factory(
+            name="updated test user",
+            email='test@testttt.fr',
+            role_names=['test role']
+        )
+        user_id = 123
+        with pytest.raises(users_exceptions.UserNotFoundError):
+            result = users_service.update_one(session, user_id, user_update)
+    
+    def test_delete_user(
+        self, 
+        session: Session, 
+        users: list[models.UserPublic]
+    ):
+        user_id = users[0].id
+        result = users_service.delete_one(session, user_id)
+
+        check = users_service.get_one(session, user_id)
+        assert check == None
+    
+    def test_delete_user_notfound(
+        self, 
+        session: Session, 
+        users: list[models.UserPublic]
+    ):
+        user_id = 123
+        with pytest.raises(users_exceptions.UserNotFoundError):
+            result = users_service.delete_one(session, user_id)
+