diff --git a/samples/audiences/create_user_list.py b/samples/audiences/create_user_list.py
new file mode 100644
index 0000000..5a0b7c3
--- /dev/null
+++ b/samples/audiences/create_user_list.py
@@ -0,0 +1,287 @@
+#!/usr/bin/env python
+# Copyright 2026 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+"""Sample of creating a user list in an operating account."""
+
+import argparse
+import datetime
+import logging
+from typing import Optional
+
+from google.ads import datamanager_v1
+
+_logger = logging.getLogger(__name__)
+
+
+# [START create-user-list]
+def main(
+    operating_account_type: datamanager_v1.ProductAccount.AccountType,
+    operating_account_id: str,
+    validate_only: bool,
+    upload_key_type: datamanager_v1.IngestedUserListInfo.UploadKeyType = (
+        datamanager_v1.IngestedUserListInfo.UploadKeyType.CONTACT_ID
+    ),
+    login_account_type: Optional[
+        datamanager_v1.ProductAccount.AccountType
+    ] = None,
+    login_account_id: Optional[str] = None,
+    linked_account_type: Optional[
+        datamanager_v1.ProductAccount.AccountType
+    ] = None,
+    linked_account_id: Optional[str] = None,
+    key_space: Optional[datamanager_v1.MobileIdInfo.KeySpace] = None,
+    app_id: Optional[str] = None,
+) -> None:
+    """Runs the sample.
+
+    Args:
+     operating_account_type: the account type of the operating account.
+     operating_account_id: the ID of the operating account.
+     validate_only: whether to enable validate_only on the request.
+     upload_key_type: the upload key type of the user list.
+     login_account_type: the account type of the login account.
+     login_account_id: the ID of the login account.
+     linked_account_type: the account type of the linked account.
+     linked_account_id: the ID of the linked account.
+     key_space: the key space of mobile IDs. Required when upload_key_type is
+       MOBILE_ID.
+     app_id: the mobile application ID. Required when upload_key_type is
+       MOBILE_ID.
+    """
+
+    # Validates parameters.
+    if bool(login_account_type) != bool(login_account_id):
+        raise ValueError(
+            "Must specify either both or neither of login account type and "
+            "login account ID"
+        )
+    if bool(linked_account_type) != bool(linked_account_id):
+        raise ValueError(
+            "Must specify either both or neither of linked account type and "
+            "linked account ID"
+        )
+    if (
+        upload_key_type
+        == datamanager_v1.IngestedUserListInfo.UploadKeyType.MOBILE_ID
+    ):
+        if not key_space or not app_id:
+            raise ValueError(
+                "Must specify both key_space and app_id when upload_key_type "
+                "is MOBILE_ID"
+            )
+    elif key_space or app_id:
+        raise ValueError(
+            "key_space and app_id are only supported when upload_key_type is "
+            "MOBILE_ID"
+        )
+
+    # Optional: Sets headers to specify the login-account and linked-account if
+    # your credentials aren't for a user in the operating account (for example,
+    # when authenticating through a Google Ads manager account or Data Partner
+    # account).
+    headers = []
+
+    if login_account_id:
+        headers.append(
+            (
+                "login-account",
+                f"accountTypes/{login_account_type}/accounts/{login_account_id}",
+            )
+        )
+
+    if linked_account_id:
+        headers.append(
+            (
+                "linked-account",
+                f"accountTypes/{linked_account_type}/accounts/{linked_account_id}",
+            )
+        )
+
+    # Configures the Customer Match user list.
+    # For more details on constructing a UserList, see:
+    # https://developers.google.com/data-manager/api/devguides/audiences/google-ads/customer-match/create-audience
+    ingested_user_list_info = datamanager_v1.IngestedUserListInfo(
+        # Sets to a list containing a single UploadKeyType.
+        upload_key_types=[upload_key_type],
+    )
+
+    if (
+        upload_key_type
+        == datamanager_v1.IngestedUserListInfo.UploadKeyType.CONTACT_ID
+    ):
+        # Use CONTACT_ID for hashed email addresses, phone numbers, or physical
+        # addresses.
+        ingested_user_list_info.contact_id_info = datamanager_v1.ContactIdInfo(
+            data_source_type=(
+                datamanager_v1.DataSourceType.DATA_SOURCE_TYPE_FIRST_PARTY
+            )
+        )
+    elif (
+        upload_key_type
+        == datamanager_v1.IngestedUserListInfo.UploadKeyType.USER_ID
+    ):
+        # Use USER_ID for first-party user IDs assigned to logged-in users.
+        ingested_user_list_info.user_id_info = datamanager_v1.UserIdInfo(
+            data_source_type=(
+                datamanager_v1.DataSourceType.DATA_SOURCE_TYPE_FIRST_PARTY
+            )
+        )
+    elif (
+        upload_key_type
+        == datamanager_v1.IngestedUserListInfo.UploadKeyType.MOBILE_ID
+    ):
+        # Use MOBILE_ID for mobile advertising IDs.
+        ingested_user_list_info.mobile_id_info = datamanager_v1.MobileIdInfo(
+            data_source_type=(
+                datamanager_v1.DataSourceType.DATA_SOURCE_TYPE_FIRST_PARTY
+            ),
+            key_space=key_space,
+            app_id=app_id,
+        )
+    else:
+        raise ValueError(f"Unsupported upload key type: {upload_key_type}")
+
+    user_list = datamanager_v1.UserList(
+        # Required. The display name must be unique among all lists owned by the
+        # account.
+        display_name=(
+            f"Customer Match ({upload_key_type.name}) - "
+            f"{datetime.datetime.now().strftime('%Y-%m-%d %H:%M:%S')}"
+        ),
+        description=f"Customer Match audience for {upload_key_type.name}",
+        # Optional. The duration an audience member remains in the list after
+        # being added. Must correspond to whole days (defaults to maximum if
+        # not set).
+        membership_duration=datetime.timedelta(days=30),
+        # Required for a Customer Match audience.
+        ingested_user_list_info=ingested_user_list_info,
+    )
+
+    # Creates a client for UserListService.
+    user_list_client = datamanager_v1.UserListServiceClient()
+
+    # Builds the request targeting the parent operating account.
+    request = datamanager_v1.CreateUserListRequest(
+        parent=f"accountTypes/{operating_account_type}/accounts/{operating_account_id}",
+        user_list=user_list,
+        # Sets validate_only. If true, then the Data Manager API only
+        # validates the request but doesn't apply changes.
+        validate_only=validate_only,
+    )
+
+    # Sends the request with any configured header metadata.
+    response: datamanager_v1.UserList = user_list_client.create_user_list(
+        request=request,
+        metadata=headers,
+    )
+
+    # Logs the created user list. When validate_only is false, response.id
+    # contains the created user list ID, which you pass as the
+    # product_destination_id in subsequent ingest or remove requests.
+    _logger.info("Response:\n%s", response)
+    # [END create-user-list]
+
+
+if __name__ == "__main__":
+    # Configures logging.
+    logging.basicConfig(level=logging.INFO)
+
+    parser = argparse.ArgumentParser(
+        description="Creates a user list in an operating account.",
+        fromfile_prefix_chars="@",
+    )
+    # The following argument(s) should be provided to run the example.
+    parser.add_argument(
+        "--operating_account_type",
+        type=str,
+        required=True,
+        help="The account type of the operating account.",
+    )
+    parser.add_argument(
+        "--operating_account_id",
+        type=str,
+        required=True,
+        help="The ID of the operating account.",
+    )
+    parser.add_argument(
+        "--upload_key_type",
+        choices=["CONTACT_ID", "USER_ID", "MOBILE_ID"],
+        default="CONTACT_ID",
+        help="The upload key type of the user list. Defaults to 'CONTACT_ID'.",
+    )
+    parser.add_argument(
+        "--login_account_type",
+        type=str,
+        required=False,
+        help="The account type of the login account.",
+    )
+    parser.add_argument(
+        "--login_account_id",
+        type=str,
+        required=False,
+        help="The ID of the login account.",
+    )
+    parser.add_argument(
+        "--linked_account_type",
+        type=str,
+        required=False,
+        help="The account type of the linked account.",
+    )
+    parser.add_argument(
+        "--linked_account_id",
+        type=str,
+        required=False,
+        help="The ID of the linked account.",
+    )
+    parser.add_argument(
+        "--key_space",
+        choices=["ANDROID", "IOS"],
+        required=False,
+        help="The key space of mobile IDs ('ANDROID' or 'IOS'). Required when "
+        "--upload_key_type is 'MOBILE_ID'.",
+    )
+    parser.add_argument(
+        "--app_id",
+        type=str,
+        required=False,
+        help="A string that uniquely identifies a mobile application from "
+        "which the data was collected (for example, 'com.labpixies.flood' for "
+        "Android or '476943146' for iOS). Required when --upload_key_type is "
+        "'MOBILE_ID'.",
+    )
+    parser.add_argument(
+        "--validate_only",
+        choices=["true", "false"],
+        default="true",
+        help="Whether to enable validate_only on the request. Must be 'true' "
+        "or 'false'. Defaults to 'true'.",
+    )
+    args = parser.parse_args()
+
+    main(
+        args.operating_account_type,
+        args.operating_account_id,
+        args.validate_only == "true",
+        datamanager_v1.IngestedUserListInfo.UploadKeyType[args.upload_key_type],
+        args.login_account_type,
+        args.login_account_id,
+        args.linked_account_type,
+        args.linked_account_id,
+        (
+            datamanager_v1.MobileIdInfo.KeySpace[args.key_space]
+            if args.key_space
+            else None
+        ),
+        args.app_id,
+    )