diff --git a/tests/unit/vertex_rag/test_rag_constants.py b/tests/unit/vertex_rag/test_rag_constants.py
index 65459cec2a..19fa4d3970 100644
--- a/tests/unit/vertex_rag/test_rag_constants.py
+++ b/tests/unit/vertex_rag/test_rag_constants.py
@@ -82,6 +82,7 @@
 TEST_CORPUS_DISPLAY_NAME = "my-corpus-1"
 TEST_CORPUS_DISCRIPTION = "My first corpus."
 TEST_RAG_CORPUS_ID = "generate-123"
+TEST_RAG_CORPUS_NUMERIC_ID = "1234567890"
 TEST_API_ENDPOINT = "us-central1-" + aiplatform.constants.base.API_BASE_PATH
 TEST_RAG_CORPUS_RESOURCE_NAME = f"projects/{TEST_PROJECT_NUMBER}/locations/{TEST_REGION}/ragCorpora/{TEST_RAG_CORPUS_ID}"
 
@@ -244,6 +245,7 @@
     TEST_API_ENDPOINT, TEST_PROJECT_NUMBER, TEST_REGION, TEST_RAG_CORPUS_ID
 )
 TEST_RAG_FILE_ID = "generate-456"
+TEST_RAG_FILE_NUMERIC_ID = "9876543210"
 TEST_RAG_FILE_RESOURCE_NAME = (
     TEST_RAG_CORPUS_RESOURCE_NAME + f"/ragFiles/{TEST_RAG_FILE_ID}"
 )
diff --git a/tests/unit/vertex_rag/test_rag_constants_preview.py b/tests/unit/vertex_rag/test_rag_constants_preview.py
index 0c0f3c810c..e41950b1a5 100644
--- a/tests/unit/vertex_rag/test_rag_constants_preview.py
+++ b/tests/unit/vertex_rag/test_rag_constants_preview.py
@@ -91,6 +91,7 @@
 TEST_CORPUS_DISPLAY_NAME = "my-corpus-1"
 TEST_CORPUS_DISCRIPTION = "My first corpus."
 TEST_RAG_CORPUS_ID = "generate-123"
+TEST_RAG_CORPUS_NUMERIC_ID = "1234567890"
 TEST_API_ENDPOINT = "us-central1-" + aiplatform.constants.base.API_BASE_PATH
 TEST_RAG_CORPUS_RESOURCE_NAME = f"projects/{TEST_PROJECT_NUMBER}/locations/{TEST_REGION}/ragCorpora/{TEST_RAG_CORPUS_ID}"
 
@@ -489,6 +490,7 @@
     TEST_API_ENDPOINT, TEST_PROJECT_NUMBER, TEST_REGION, TEST_RAG_CORPUS_ID
 )
 TEST_RAG_FILE_ID = "generate-456"
+TEST_RAG_FILE_NUMERIC_ID = "9876543210"
 TEST_RAG_FILE_RESOURCE_NAME = (
     TEST_RAG_CORPUS_RESOURCE_NAME + f"/ragFiles/{TEST_RAG_FILE_ID}"
 )
diff --git a/tests/unit/vertex_rag/test_rag_data.py b/tests/unit/vertex_rag/test_rag_data.py
index 94f6c35bf9..adc67c70c2 100644
--- a/tests/unit/vertex_rag/test_rag_data.py
+++ b/tests/unit/vertex_rag/test_rag_data.py
@@ -663,6 +663,26 @@ def test_get_corpus_id_success(self):
         rag_corpus = rag.get_corpus(test_rag_constants.TEST_RAG_CORPUS_ID)
         rag_corpus_eq(rag_corpus, test_rag_constants.TEST_RAG_CORPUS)
 
+    def test_get_corpus_numeric_id_success(self):
+        """Bare numeric IDs must pass the regex and be expanded to full resource names."""
+        with mock.patch.object(
+            rag.utils._gapic_utils, "create_rag_data_service_client"
+        ) as mock_client_factory:
+            api_client_mock = mock.Mock(spec=VertexRagDataServiceClient)
+            api_client_mock.parse_rag_corpus_path.side_effect = (
+                VertexRagDataServiceClient.parse_rag_corpus_path
+            )
+            api_client_mock.rag_corpus_path.side_effect = (
+                VertexRagDataServiceClient.rag_corpus_path
+            )
+            api_client_mock.get_rag_corpus.return_value = (
+                test_rag_constants.TEST_GAPIC_RAG_CORPUS
+            )
+            mock_client_factory.return_value = api_client_mock
+
+            rag_corpus = rag.get_corpus(test_rag_constants.TEST_RAG_CORPUS_NUMERIC_ID)
+            rag_corpus_eq(rag_corpus, test_rag_constants.TEST_RAG_CORPUS)
+
     @pytest.mark.usefixtures("rag_data_client_mock_exception")
     def test_get_corpus_failure(self):
         with pytest.raises(RuntimeError) as e:
@@ -883,6 +903,35 @@ def test_get_file_id_success(self):
         )
         rag_file_eq(rag_file, test_rag_constants.TEST_RAG_FILE)
 
+    def test_get_file_numeric_id_success(self):
+        """Bare numeric IDs must pass the regex and be expanded to full resource names."""
+        with mock.patch.object(
+            rag.utils._gapic_utils, "create_rag_data_service_client"
+        ) as mock_client_factory:
+            api_client_mock = mock.Mock(spec=VertexRagDataServiceClient)
+            api_client_mock.parse_rag_corpus_path.side_effect = (
+                VertexRagDataServiceClient.parse_rag_corpus_path
+            )
+            api_client_mock.parse_rag_file_path.side_effect = (
+                VertexRagDataServiceClient.parse_rag_file_path
+            )
+            api_client_mock.rag_corpus_path.side_effect = (
+                VertexRagDataServiceClient.rag_corpus_path
+            )
+            api_client_mock.rag_file_path.side_effect = (
+                VertexRagDataServiceClient.rag_file_path
+            )
+            api_client_mock.get_rag_file.return_value = (
+                test_rag_constants.TEST_GAPIC_RAG_FILE
+            )
+            mock_client_factory.return_value = api_client_mock
+
+            rag_file = rag.get_file(
+                name=test_rag_constants.TEST_RAG_FILE_NUMERIC_ID,
+                corpus_name=test_rag_constants.TEST_RAG_CORPUS_NUMERIC_ID,
+            )
+            rag_file_eq(rag_file, test_rag_constants.TEST_RAG_FILE)
+
     @pytest.mark.usefixtures("rag_data_client_mock_exception")
     def test_get_file_failure(self):
         with pytest.raises(RuntimeError) as e:
diff --git a/tests/unit/vertex_rag/test_rag_data_preview.py b/tests/unit/vertex_rag/test_rag_data_preview.py
index b1e7d4c3b0..2acbdb87ff 100644
--- a/tests/unit/vertex_rag/test_rag_data_preview.py
+++ b/tests/unit/vertex_rag/test_rag_data_preview.py
@@ -1315,6 +1315,28 @@ def test_get_corpus_id_success(self):
         rag_corpus = rag.get_corpus(test_rag_constants_preview.TEST_RAG_CORPUS_ID)
         rag_corpus_eq(rag_corpus, test_rag_constants_preview.TEST_RAG_CORPUS)
 
+    def test_get_corpus_numeric_id_success(self):
+        """Bare numeric IDs must pass the regex and be expanded to full resource names."""
+        with mock.patch.object(
+            rag.utils._gapic_utils, "create_rag_data_service_client"
+        ) as mock_client_factory:
+            api_client_mock = mock.Mock(spec=VertexRagDataServiceClient)
+            api_client_mock.parse_rag_corpus_path.side_effect = (
+                VertexRagDataServiceClient.parse_rag_corpus_path
+            )
+            api_client_mock.rag_corpus_path.side_effect = (
+                VertexRagDataServiceClient.rag_corpus_path
+            )
+            api_client_mock.get_rag_corpus.return_value = (
+                test_rag_constants_preview.TEST_GAPIC_RAG_CORPUS
+            )
+            mock_client_factory.return_value = api_client_mock
+
+            rag_corpus = rag.get_corpus(
+                test_rag_constants_preview.TEST_RAG_CORPUS_NUMERIC_ID
+            )
+            rag_corpus_eq(rag_corpus, test_rag_constants_preview.TEST_RAG_CORPUS)
+
     @pytest.mark.usefixtures("rag_data_client_preview_mock_exception")
     def test_get_corpus_failure(self):
         with pytest.raises(RuntimeError) as e:
@@ -1454,6 +1476,35 @@ def test_get_file_id_success(self):
         )
         rag_file_eq(rag_file, test_rag_constants_preview.TEST_RAG_FILE)
 
+    def test_get_file_numeric_id_success(self):
+        """Bare numeric IDs must pass the regex and be expanded to full resource names."""
+        with mock.patch.object(
+            rag.utils._gapic_utils, "create_rag_data_service_client"
+        ) as mock_client_factory:
+            api_client_mock = mock.Mock(spec=VertexRagDataServiceClient)
+            api_client_mock.parse_rag_corpus_path.side_effect = (
+                VertexRagDataServiceClient.parse_rag_corpus_path
+            )
+            api_client_mock.parse_rag_file_path.side_effect = (
+                VertexRagDataServiceClient.parse_rag_file_path
+            )
+            api_client_mock.rag_corpus_path.side_effect = (
+                VertexRagDataServiceClient.rag_corpus_path
+            )
+            api_client_mock.rag_file_path.side_effect = (
+                VertexRagDataServiceClient.rag_file_path
+            )
+            api_client_mock.get_rag_file.return_value = (
+                test_rag_constants_preview.TEST_GAPIC_RAG_FILE
+            )
+            mock_client_factory.return_value = api_client_mock
+
+            rag_file = rag.get_file(
+                name=test_rag_constants_preview.TEST_RAG_FILE_NUMERIC_ID,
+                corpus_name=test_rag_constants_preview.TEST_RAG_CORPUS_NUMERIC_ID,
+            )
+            rag_file_eq(rag_file, test_rag_constants_preview.TEST_RAG_FILE)
+
     @pytest.mark.usefixtures("rag_data_client_preview_mock_exception")
     def test_get_file_failure(self):
         with pytest.raises(RuntimeError) as e:
diff --git a/vertexai/preview/rag/utils/_gapic_utils.py b/vertexai/preview/rag/utils/_gapic_utils.py
index 4150111c60..5bcb1e9a8e 100644
--- a/vertexai/preview/rag/utils/_gapic_utils.py
+++ b/vertexai/preview/rag/utils/_gapic_utils.py
@@ -78,7 +78,8 @@
 )
 
 
-_VALID_RESOURCE_NAME_REGEX = "[a-z][a-zA-Z0-9._-]{0,127}"
+# Allows numeric resource IDs (e.g. "1234567890") as bare names.
+_VALID_RESOURCE_NAME_REGEX = "[a-zA-Z0-9][a-zA-Z0-9._-]{0,127}"
 _VALID_DOCUMENT_AI_PROCESSOR_NAME_REGEX = (
     r"projects/[^/]+/locations/[^/]+/processors/[^/]+(?:/processorVersions/[^/]+)?"
 )
diff --git a/vertexai/rag/utils/_gapic_utils.py b/vertexai/rag/utils/_gapic_utils.py
index 3ee39a7a0f..6535767b71 100644
--- a/vertexai/rag/utils/_gapic_utils.py
+++ b/vertexai/rag/utils/_gapic_utils.py
@@ -67,7 +67,8 @@
 )
 
 
-_VALID_RESOURCE_NAME_REGEX = "[a-z][a-zA-Z0-9._-]{0,127}"
+# Allows numeric resource IDs (e.g. "1234567890") as bare names.
+_VALID_RESOURCE_NAME_REGEX = "[a-zA-Z0-9][a-zA-Z0-9._-]{0,127}"
 _VALID_DOCUMENT_AI_PROCESSOR_NAME_REGEX = (
     r"projects/[^/]+/locations/[^/]+/processors/[^/]+(?:/processorVersions/[^/]+)?"
 )