diff --git a/.pre-commit-config.yaml b/.pre-commit-config.yaml
index b93a3a5..62947c0 100644
--- a/.pre-commit-config.yaml
+++ b/.pre-commit-config.yaml
@@ -57,3 +57,8 @@ repos:
         language: system
         types: ['markdown']
         exclude: .github/
+      - id: pydocstyle
+        name: pydocstyle
+        entry: poetry run pydocstyle --convention=google
+        language: system
+        types: ['python']
diff --git a/poetry.lock b/poetry.lock
index 5cf0839..f6a6a76 100644
--- a/poetry.lock
+++ b/poetry.lock
@@ -2493,6 +2493,23 @@ typing-extensions = ">=4.2.0"
 dotenv = ["python-dotenv (>=0.10.4)"]
 email = ["email-validator (>=1.0.3)"]
 
+[[package]]
+name = "pydocstyle"
+version = "6.3.0"
+description = "Python docstring style checker"
+optional = false
+python-versions = ">=3.6"
+files = [
+    {file = "pydocstyle-6.3.0-py3-none-any.whl", hash = "sha256:118762d452a49d6b05e194ef344a55822987a462831ade91ec5c06fd2169d019"},
+    {file = "pydocstyle-6.3.0.tar.gz", hash = "sha256:7ce43f0c0ac87b07494eb9c0b462c0b73e6ff276807f204d6b53edc72b7e44e1"},
+]
+
+[package.dependencies]
+snowballstemmer = ">=2.2.0"
+
+[package.extras]
+toml = ["tomli (>=1.2.3)"]
+
 [[package]]
 name = "pyflakes"
 version = "2.3.1"
@@ -3153,6 +3170,17 @@ files = [
     {file = "sniffio-1.3.0.tar.gz", hash = "sha256:e60305c5e5d314f5389259b7f22aaa33d8f7dee49763119234af3755c55b9101"},
 ]
 
+[[package]]
+name = "snowballstemmer"
+version = "2.2.0"
+description = "This package provides 29 stemmers for 28 languages generated from Snowball algorithms."
+optional = false
+python-versions = "*"
+files = [
+    {file = "snowballstemmer-2.2.0-py2.py3-none-any.whl", hash = "sha256:c8e1716e83cc398ae16824e5572ae04e0d9fc2c6b985fb0f900f5f0c96ecba1a"},
+    {file = "snowballstemmer-2.2.0.tar.gz", hash = "sha256:09b16deb8547d3412ad7b590689584cd0fe25ec8db3be37788be3810cbf19cb1"},
+]
+
 [[package]]
 name = "sortedcontainers"
 version = "2.4.0"
@@ -3701,4 +3729,4 @@ files = [
 [metadata]
 lock-version = "2.0"
 python-versions = ">=3.10 <3.12"
-content-hash = "7fb2a1b2601f83e44af9a05d6033785f2e377d0626b77bc4cdefef4857a576ea"
+content-hash = "049168b9b2c4a52107663cd6ee0ebe97d252d5855a0560bd6b8553860403f53f"
diff --git a/pyproject.toml b/pyproject.toml
index da2e32e..d6b6cf7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -49,6 +49,7 @@ pytest-mock = "^3.6.1"
 requests = "^2.25.1"
 safety = "^2.3.1"
 sqlalchemy-stubs = "^0.3"
+pydocstyle = "^6.3.0"
 
 [tool.isort]
 profile = "black"
diff --git a/rctab/main.py b/rctab/main.py
index 86ee709..d128bcf 100644
--- a/rctab/main.py
+++ b/rctab/main.py
@@ -168,6 +168,5 @@ async def get_documentation(_: Dict = Depends(user_authenticated)) -> HTMLRespon
 
 @app.get("/redoc", include_in_schema=False)
 async def get_redocumentation(_: Dict = Depends(user_authenticated)) -> HTMLResponse:
-    """Serves redoc API docs."""
-
+    """Serves Redoc API docs."""
     return get_redoc_html(openapi_url="/openapi.json", title="docs")
diff --git a/rctab/utils.py b/rctab/utils.py
index a946bcb..1642b71 100644
--- a/rctab/utils.py
+++ b/rctab/utils.py
@@ -1,3 +1,4 @@
+"""Utility functions for the RCTab API."""
 import functools
 import logging
 from contextlib import contextmanager
@@ -24,7 +25,7 @@ def wrapping_logic(statement: Any) -> Generator:
     def _db_select(
         *args: Any, execute: bool = True, raise_404: bool = True, **kwargs: Any
     ) -> Coroutine:
-        "Select and raise a 404 if no data is returned"
+        """Select and raise a 404 if no data is returned."""
         statement = func(*args, **kwargs)
 
         if execute:
diff --git a/tests/test_crud/__init__.py b/tests/test_crud/__init__.py
index e69de29..8e5ee9e 100644
--- a/tests/test_crud/__init__.py
+++ b/tests/test_crud/__init__.py
@@ -0,0 +1 @@
+"""Test the database-related functionality."""
diff --git a/tests/test_routes/api_calls.py b/tests/test_routes/api_calls.py
index fb40b44..3176475 100644
--- a/tests/test_routes/api_calls.py
+++ b/tests/test_routes/api_calls.py
@@ -23,6 +23,7 @@
 def assert_subscription_status(
     client: TestClient, expected_details: SubscriptionDetails
 ) -> None:
+    """Assert that the subscription details are as expected."""
     result = client.get(
         PREFIX + "/subscription",
         params={"sub_id": str(expected_details.subscription_id)},
@@ -43,6 +44,7 @@ def assert_subscription_status(
 
 
 def create_subscription(client: TestClient, subscription_id: UUID) -> Response:
+    """Create a subscription record."""
     return client.post(
         PREFIX + "/subscription",
         json={"sub_id": str(subscription_id)},
@@ -57,6 +59,7 @@ def create_subscription_detail(
     role_assignments: Optional[Tuple[RoleAssignment, ...]] = (),
     display_name: str = "sub display name",
 ) -> Response:
+    """Create a subscription detail record."""
     return client.post(
         "accounting" + "/all-status",
         content=AllSubscriptionStatus(
@@ -76,6 +79,7 @@ def create_subscription_detail(
 def set_persistence(
     client: TestClient, subscription_id: UUID, always_on: bool
 ) -> Response:
+    """Set the persistence of a subscription."""
     return client.post(
         PREFIX + "/persistent",
         json={"sub_id": str(subscription_id), "always_on": always_on},
@@ -93,6 +97,7 @@ def create_approval(
     currency: str = "GBP",
     force: bool = False,
 ) -> Response:
+    """Create an approval for a subscription."""
     return client.post(
         PREFIX + "/approve",
         json={
@@ -114,6 +119,7 @@ def create_allocation(
     ticket: str,
     amount: float,
 ) -> Response:
+    """Create an allocation for a subscription."""
     return client.post(
         PREFIX + "/topup",
         json={"sub_id": str(subscription_id), "ticket": ticket, "amount": amount},
@@ -128,6 +134,7 @@ def create_usage(
     amortised_cost: float = 0.0,
     date: datetime.date = datetime.date.today(),
 ) -> Response:
+    """Create a usage record for a subscription."""
     usage = Usage(
         id=str(uuid4()),
         name="test",