diff --git a/pv_site_api/fake.py b/pv_site_api/fake.py
index dd3417f..b555ee1 100644
--- a/pv_site_api/fake.py
+++ b/pv_site_api/fake.py
@@ -24,7 +24,7 @@ def make_fake_site() -> PVSites:
     pv_site = PVSiteMetadata(
         site_uuid=fake_site_uuid,
         client_name="client_name_1",
-        client_site_id="the site id used by the user",
+        client_site_id=1,
         client_site_name="the site name",
         region="the site's region",
         dno="the site's dno",
diff --git a/pv_site_api/pydantic_models.py b/pv_site_api/pydantic_models.py
index ae561ea..5caaf52 100644
--- a/pv_site_api/pydantic_models.py
+++ b/pv_site_api/pydantic_models.py
@@ -30,7 +30,7 @@ class PVSiteAPIStatus(BaseModel):
 class PVSiteInputMetadata(BaseModel):
     """Site metadata when adding a site"""
 
-    client_site_id: str = Field(..., description="The site ID as given by the providing user.")
+    client_site_id: int = Field(..., description="The site ID as given by the providing user.")
     client_site_name: str = Field(
         None, decription="The name of the site as given by the providing user."
     )
diff --git a/tests/test_sites.py b/tests/test_sites.py
index 3264122..e12a835 100644
--- a/tests/test_sites.py
+++ b/tests/test_sites.py
@@ -50,7 +50,7 @@ def test_get_site_list_min(client, sites):
 def test_put_site_fake(client, fake):
     pv_site = PVSiteInputMetadata(
         client_name="client_name_1",
-        client_site_id="the site id used by the user",
+        client_site_id=1,
         client_site_name="the site name",
         region="the site's region",
         dno="the site's dno",