diff --git a/rbac/management/principal/it_service.py b/rbac/management/principal/it_service.py
index ac05c2291..c7788e0e7 100644
--- a/rbac/management/principal/it_service.py
+++ b/rbac/management/principal/it_service.py
@@ -250,9 +250,10 @@ def get_service_accounts(self, user: User, options: dict[str, Any] = {}) -> Tupl
         if specified_usernames:
             usernames = specified_usernames.split(",")
 
-        # If "match_criteria" is specified, only the first username is taken into account.
+        # If "match_criteria" is specified and the usernames list is not empty,
+        # only the first username is taken into account
         match_criteria = options.get("match_criteria")
-        if match_criteria:
+        if match_criteria and usernames:
             username = usernames[0]
 
             if match_criteria == "partial":
diff --git a/tests/management/principal/test_it_service.py b/tests/management/principal/test_it_service.py
index 0a8d94c65..3064a3c0e 100644
--- a/tests/management/principal/test_it_service.py
+++ b/tests/management/principal/test_it_service.py
@@ -1570,3 +1570,53 @@ def test_merge_principals_it_service_accounts(self) -> None:
                 f' "{expected_first_username}" or "{expected_second_username}", got the following service account:'
                 f" {filtered_result}",
             )
+
+    @override_settings(IT_BYPASS_IT_CALLS=True)
+    def test_principal_filtering_without_username_match_criteria_exact_skipped(self):
+        """Test the function under test skips the expected service account when filtering by exact match criteria without usernames"""
+        user = User()
+        user.account = self.tenant.account_id
+        user.org_id = self.tenant.org_id
+
+        # Set the options for the filter.
+        options = {
+            "limit": 10,
+            "offset": 0,
+            "match_criteria": "exact",
+            "usernames": None,
+        }
+
+        # Call the function under test.
+        result, count = self.it_service.get_service_accounts(user=user, options=options)
+        print(result)
+        print(count)
+        self.assertEqual(
+            0,
+            count,
+            "unexpected number of service accounts fetched for the tenant",
+        )
+
+    @override_settings(IT_BYPASS_IT_CALLS=True)
+    def test_principal_filtering_without_username_match_criteria_partial_skipped(self):
+        """Test the function under test skips the expected service account when match_criteria is partial without usernames"""
+        user = User()
+        user.account = self.tenant.account_id
+        user.org_id = self.tenant.org_id
+
+        # Set the options for the filter.
+        options = {
+            "limit": 10,
+            "offset": 0,
+            "match_criteria": "partial",
+            "usernames": None,
+        }
+
+        # Call the function under test.
+        result, count = self.it_service.get_service_accounts(user=user, options=options)
+        print(result)
+        print(count)
+        self.assertEqual(
+            0,
+            count,
+            "unexpected number of service accounts fetched for the tenant",
+        )