diff --git a/api/integrations/lead_tracking/hubspot/lead_tracker.py b/api/integrations/lead_tracking/hubspot/lead_tracker.py
index b7347443d76c..510e0976fb44 100644
--- a/api/integrations/lead_tracking/hubspot/lead_tracker.py
+++ b/api/integrations/lead_tracking/hubspot/lead_tracker.py
@@ -56,7 +56,9 @@ def create_lead(self, user: FFAdminUser, organisation: Organisation = None) -> N
 
         response = self.client.create_contact(user, hubspot_id)
 
-        HubspotLead.objects.create(user=user, hubspot_id=response["id"])
+        HubspotLead.objects.update_or_create(
+            user=user, defaults={"hubspot_id": response["id"]}
+        )
 
         if tracker := HubspotTracker.objects.filter(user=user).first():
             self.client.create_lead_form(
diff --git a/api/tests/unit/integrations/lead_tracking/hubspot/test_unit_hubspot_lead_tracking.py b/api/tests/unit/integrations/lead_tracking/hubspot/test_unit_hubspot_lead_tracking.py
index 587cbf6ca0a2..04af3df92474 100644
--- a/api/tests/unit/integrations/lead_tracking/hubspot/test_unit_hubspot_lead_tracking.py
+++ b/api/tests/unit/integrations/lead_tracking/hubspot/test_unit_hubspot_lead_tracking.py
@@ -279,6 +279,78 @@ def test_hubspot_with_new_contact_and_existing_organisation(
     mock_get_contact.assert_called_once_with(user)
 
 
+def test_hubspot_with_new_contact_and_existing_organisation_with_hubspot_duplicate(
+    organisation: Organisation,
+    settings: SettingsWrapper,
+    mocker: MockerFixture,
+) -> None:
+    # Given
+    settings.ENABLE_HUBSPOT_LEAD_TRACKING = True
+    user = FFAdminUser.objects.create(
+        email="new.user@example.com",
+        first_name="Frank",
+        last_name="Louis",
+        marketing_consent_given=True,
+    )
+
+    former_hubspot_id = "1023333333"
+    HubspotLead.objects.create(user=user, hubspot_id=former_hubspot_id)
+
+    hubspot_id = "10280696017"
+
+    # Create an existing hubspot organisation to mimic a previous
+    # successful API call with a different lead.
+    HubspotOrganisation.objects.create(organisation=organisation, hubspot_id=hubspot_id)
+
+    mock_create_company = mocker.patch(
+        "integrations.lead_tracking.hubspot.client.HubspotClient.create_company"
+    )
+    mock_get_contact = mocker.patch(
+        "integrations.lead_tracking.hubspot.client.HubspotClient.get_contact",
+        return_value=None,
+    )
+
+    hubspot_lead_id = "1000551"
+    mock_create_contact = mocker.patch(
+        "integrations.lead_tracking.hubspot.client.HubspotClient.create_contact",
+        return_value={
+            "archived": False,
+            "archived_at": None,
+            "created_at": datetime.datetime(2024, 2, 26, 20, 2, 50, 69000),
+            "id": hubspot_lead_id,
+            "properties": {
+                "createdate": "2024-02-26T20:02:50.069Z",
+                "email": user.email,
+                "firstname": user.first_name,
+                "hs_all_contact_vids": "1000551",
+                "hs_email_domain": "example.com",
+                "hs_is_contact": "true",
+                "hs_is_unworked": "true",
+                "hs_marketable_status": user.marketing_consent_given,
+                "hs_object_id": "1000551",
+                "hs_object_source": "INTEGRATION",
+                "hs_object_source_id": "2902325",
+                "hs_object_source_label": "INTEGRATION",
+                "hs_pipeline": "contacts-lifecycle-pipeline",
+                "lastmodifieddate": "2024-02-26T20:02:50.069Z",
+                "lastname": user.last_name,
+            },
+            "properties_with_history": None,
+            "updated_at": datetime.datetime(2024, 2, 26, 20, 2, 50, 69000),
+        },
+    )
+
+    # When
+    user.add_organisation(organisation, role=OrganisationRole.ADMIN)
+
+    # Then
+    assert HubspotLead.objects.filter(hubspot_id=hubspot_lead_id).exists() is True
+    assert HubspotLead.objects.filter(hubspot_id=former_hubspot_id).exists() is False
+    mock_create_company.assert_not_called()
+    mock_create_contact.assert_called_once_with(user, hubspot_id)
+    mock_get_contact.assert_called_once_with(user)
+
+
 def test_hubspot_with_existing_contact_and_new_organisation(
     organisation: Organisation,
     settings: SettingsWrapper,