diff --git a/litellm/llms/sap/credentials.py b/litellm/llms/sap/credentials.py
index 11a455b6373..1ecdf09fc4f 100644
--- a/litellm/llms/sap/credentials.py
+++ b/litellm/llms/sap/credentials.py
@@ -286,8 +286,7 @@ def fetch_credentials(
 
     resource_group = resolve_resource_group(sources)
 
-    if resource_group is not None:
-        credentials["resource_group"] = resource_group
+    credentials["resource_group"] = resource_group
 
     if "cert_url" in credentials:
         credentials["auth_url"] = credentials.pop("cert_url")
@@ -313,8 +312,8 @@ def validate_credentials(
 
     modes = [
         bool(client_secret),
-        (cert_str is not None and key_str is not None),
-        (cert_file_path is not None and key_file_path is not None),
+        bool(cert_str) and bool(key_str),
+        bool(cert_file_path) and bool(key_file_path),
     ]
     if sum(bool(m) for m in modes) != 1:
         raise ValueError(
diff --git a/tests/test_litellm/llms/sap/test_sap_fetch_creds.py b/tests/test_litellm/llms/sap/test_sap_fetch_creds.py
index be9721512db..77e2848f737 100644
--- a/tests/test_litellm/llms/sap/test_sap_fetch_creds.py
+++ b/tests/test_litellm/llms/sap/test_sap_fetch_creds.py
@@ -105,4 +105,19 @@ def test_partial_credentials_missing_auth_url(monkeypatch):
     creds.pop('resource_group')
 
     with pytest.raises(ValueError, match="SAP AI Core credentials not found."):
-        sap_credentials.validate_credentials(**creds)
\ No newline at end of file
+        sap_credentials.validate_credentials(**creds)
+
+def test_credentials_without_authentication_mode(monkeypatch):
+    _prep_env(monkeypatch)
+
+    # Set all required fields but no authentication mode (no client_secret, no certs)
+    monkeypatch.setenv("AICORE_CLIENT_ID", "test-client-id")
+    monkeypatch.setenv("AICORE_AUTH_URL", "test-auth-url")
+    monkeypatch.setenv("AICORE_BASE_URL", "test-base-url")
+
+    creds = sap_credentials.fetch_credentials()
+    creds.pop('resource_group')
+
+    # validate_credentials should raise because no authentication mode is provided
+    with pytest.raises(ValueError, match="SAP AI Core credentials are incomplete."):
+        sap_credentials.validate_credentials(**creds)