diff --git a/queue_services/business-filer/devops/vaults.gcp.env b/queue_services/business-filer/devops/vaults.gcp.env
index 82ba9a05ee..2361bc9d14 100644
--- a/queue_services/business-filer/devops/vaults.gcp.env
+++ b/queue_services/business-filer/devops/vaults.gcp.env
@@ -38,6 +38,7 @@ BUSINESS_EVENTS_TOPIC="op://gcp-queue/$APP_ENV/topics/BUSINESS_EVENTS_TOPIC"
 BUSINESS_MAILER_TOPIC="op://gcp-queue/$APP_ENV/topics/BUSINESS_EMAILER_TOPIC"
 BUSINESS_PAY_TOPIC="op://gcp-queue/$APP_ENV/topics/BUSINESS_PAY_TOPIC"
 DOC_CREATE_REC_TOPIC="op://gcp-queue/$APP_ENV/topics/DOC_CREATE_REC_TOPIC"
+DOC_UPDATE_REC_TOPIC="op://gcp-queue/$APP_ENV/topics/DOC_UPDATE_REC_TOPIC"
 NAMEX_PAY_TOPIC="op://gcp-queue/$APP_ENV/topics/NAMEX_PAY_TOPIC"
 VPC_CONNECTOR="op://CD/$APP_ENV/base/VPC_CONNECTOR"
 
diff --git a/queue_services/business-filer/src/business_filer/config.py b/queue_services/business-filer/src/business_filer/config.py
index 92c50bbae1..a4ba1974a6 100644
--- a/queue_services/business-filer/src/business_filer/config.py
+++ b/queue_services/business-filer/src/business_filer/config.py
@@ -92,6 +92,7 @@ class _Config:  # pylint: disable=too-few-public-methods
     BUSINESS_MAILER_TOPIC = os.getenv("BUSINESS_MAILER_TOPIC", "business-mailer-dev")
     BUSINESS_PAY_TOPIC = os.getenv("BUSINESS_PAY_TOPIC", "business-pay-dev")
     DOC_CREATE_REC_TOPIC = os.getenv("DOC_CREATE_REC_TOPIC")
+    DOC_UPDATE_REC_TOPIC = os.getenv("DOC_UPDATE_REC_TOPIC")
     NAMEX_PAY_TOPIC = os.getenv("NAMEX_PAY_TOPIC", "namex-pay-dev")
     SUB_AUDIENCE = os.getenv("SUB_AUDIENCE", "")
     SUB_SERVICE_ACCOUNT = os.getenv("SUB_SERVICE_ACCOUNT", "")
@@ -132,6 +133,7 @@ class TestConfig(_Config):  # pylint: disable=too-few-public-methods
     
     # Faked out publishing
     DOC_CREATE_REC_TOPIC = os.getenv("TEST_DOC_CREATE_REC_TOPIC", "fake-doc-create-rec-topic")
+    DOC_UPDATE_REC_TOPIC = os.getenv("TEST_DOC_UPDATE_REC_TOPIC", "fake-doc-update-rec-topic")
 
 
 class ProdConfig(_Config):  # pylint: disable=too-few-public-methods
diff --git a/queue_services/business-filer/src/business_filer/filing_processors/filing_components/document_records.py b/queue_services/business-filer/src/business_filer/filing_processors/filing_components/document_records.py
deleted file mode 100644
index 39b9da275f..0000000000
--- a/queue_services/business-filer/src/business_filer/filing_processors/filing_components/document_records.py
+++ /dev/null
@@ -1,81 +0,0 @@
-# Copyright © 2026 Province of British Columbia
-#
-# 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
-#
-#     http://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.
-"""Updates client document records with filing/business information once a filing completes,
-so the document shows up correctly in the ledger and is searchable in the DRS UI.
-"""
-import re
-
-from business_model.models import Business, Document, Filing
-from flask import current_app
-
-from business_filer.services import document_service
-
-_DRS_KEY_PATTERN = re.compile(r"^[A-Z]+-DS\d+$")
-
-
-def update_document_records(business: Business, filing: Filing):
-    """Update the document record(s) for any client documents uploaded via DRS associated with a filing.
-
-    business: The business record associated with the filing.
-    filing: The completed filing record.
-    """
-
-    documents = _find_documents_for_filing(filing.id)
-
-    if not documents:
-        return
-
-    update_info = _build_update_info(business, filing)
-
-    for document in documents:
-        if not _is_drs_document(document.file_key):
-            continue
-        try:
-            response = document_service.update_document_record(document.file_key, dict(update_info))
-            if response is not None and not response.ok:
-                current_app.logger.warning(
-                    f"Failed to update document record for document id={document.id}, "
-                    f"file_key={document.file_key}, filing={filing.id}: "
-                    f"status={response.status_code}, body={document_service.get_content(response)}"
-                )
-        except Exception as err:  # pylint: disable=broad-except
-            current_app.logger.warning(
-                f"Error updating document record for document id={document.id}, "
-                f"file_key={document.file_key}, filing={filing.id}: {err}"
-            )
-
-
-def _find_documents_for_filing(filing_id: int) -> list[Document]:
-    """Find all documents for a filing."""
-    return Document.query.filter_by(filing_id=filing_id).all()
-
-
-def _build_update_info(business: Business, filing: Filing) -> dict:
-    """Build the update payload."""
-    update_info = {
-        "filingId": filing.id,
-        "filingDate": filing.completion_date.isoformat() if filing.completion_date else None,
-    }
-    if business:
-        update_info["businessIdentifier"] = business.identifier
-    return {k: v for k, v in update_info.items() if v is not None}
-
-
-def _is_drs_document(file_key: str) -> bool:
-    """Return True if the file_key is a DRS key.
-
-    DRS keys are formatted as "{documentClass}-{documentServiceId}", e.g. "COOP-DS0000101951".
-    Legacy Minio keys (UUIDs) do not match this pattern.
-    """
-    return bool(file_key) and bool(_DRS_KEY_PATTERN.match(file_key))
diff --git a/queue_services/business-filer/src/business_filer/services/__init__.py b/queue_services/business-filer/src/business_filer/services/__init__.py
index 04fbd6e653..4e52d7b98b 100644
--- a/queue_services/business-filer/src/business_filer/services/__init__.py
+++ b/queue_services/business-filer/src/business_filer/services/__init__.py
@@ -36,7 +36,6 @@
 
 from ..common.services.account_service import AccountService  # noqa: TID252
 from ..common.services.flag_manager import Flags  # noqa: TID252
-from . import document_service
 from .gcp_auth import verify_gcp_jwt
 
 flags = Flags()
diff --git a/queue_services/business-filer/src/business_filer/services/document_service.py b/queue_services/business-filer/src/business_filer/services/document_service.py
deleted file mode 100644
index e876c6aa1f..0000000000
--- a/queue_services/business-filer/src/business_filer/services/document_service.py
+++ /dev/null
@@ -1,73 +0,0 @@
-# Copyright © 2026 Province of British Columbia
-#
-# 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
-#
-#     http://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.
-"""Manages Filer -> DRS integration for updating client document records after a filing completes."""
-import json
-
-import requests
-from flask import current_app
-
-from business_filer.services import AccountService
-
-PATCH_DOCUMENT_PATH: str = "{url}/documents/client/{document_key}"
-SERVICE_TIMEOUT = 30.0
-
-
-def update_document_record(document_key: str, update_info: dict):
-    """Update document record properties via the Business API documents endpoint.
-
-    Business API reference: PATCH /business/api/v2/documents/client/{documentKey}
-
-    document_key: The business documents table file_key value, formatted as
-        "{documentClass}-{documentServiceId}".
-    update_info: The properties to update - any of filingId, filingDate, businessIdentifier.
-    return: The Business API response, or None if no document_key is available to update.
-    """
-    if not document_key:
-        current_app.logger.info("update_document_record aborted: no document file_key.")
-        return None
-    url = PATCH_DOCUMENT_PATH.format(
-        url=str(current_app.config.get("LEGAL_API_URL")).rstrip("/"),
-        document_key=document_key
-    )
-    headers = _get_request_headers()
-    current_app.logger.info(f"Business API update_document_record url={url}")
-    response = requests.patch(url=url, headers=headers, timeout=SERVICE_TIMEOUT, json=update_info)
-    current_app.logger.info(f"Business API patch call {url} status={response.status_code}")
-    if not response.ok:
-        current_app.logger.error(f"Business API patch call {url} response={response.content}")
-    return response
-
-
-def _get_request_headers() -> dict:
-    """Get request headers."""
-    headers = {
-        **AccountService.CONTENT_TYPE_JSON
-    }
-
-    if current_app.config.get("ACCOUNT_SVC_CLIENT_SECRET"):
-        token = AccountService.get_bearer_token()
-        headers["Authorization"] = AccountService.BEARER + token
-
-    return headers
-
-
-def get_content(response):
-    """Get the content of the response useful for test methods."""
-    content = response.content
-    try:
-        content = content.decode()
-        content = json.loads(content)
-    except Exception:  # pylint: disable=broad-except; best-effort parsing only
-        pass
-    return content
diff --git a/queue_services/business-filer/src/business_filer/services/filer.py b/queue_services/business-filer/src/business_filer/services/filer.py
index d191652078..fc3ffb8d10 100644
--- a/queue_services/business-filer/src/business_filer/services/filer.py
+++ b/queue_services/business-filer/src/business_filer/services/filer.py
@@ -78,7 +78,7 @@
     transition,
     transparency_register,
 )
-from business_filer.filing_processors.filing_components import business_profile, document_records, name_request
+from business_filer.filing_processors.filing_components import business_profile, name_request
 from business_filer.services import Flags
 from business_filer.services.publish_event import PublishEvent
 
@@ -326,9 +326,14 @@ def process_filing(filing_message: FilingMessage): # noqa: PLR0915, PLR0912
         if not Flags.is_on("enable-sandbox"):
             PublishEvent.publish_email_message(current_app, business, filing_submission, filing_submission.status)
 
-        # Update the document record(s) for any client-submitted documents on this filing with
-        # the filing id, filing date, and business identifier
-        document_records.update_document_records(business, filing_submission)
+        try:
+            # Update the DRS record(s) for any client-submitted documents on this filing with
+            # the filing id, filing date, and business identifier
+            PublishEvent.publish_drs_update_message(current_app, business, filing_submission)
+        except Exception as err:
+            # log error for ops, but don't prevent filing from completing
+            current_app.logger.warning(err.with_traceback(None))
+            current_app.logger.warning(f"Failed to publish DRS update for {filing_submission.id}.")
 
         if filing_type in [
             FilingTypes.CHANGEOFLIQUIDATORS,
diff --git a/queue_services/business-filer/src/business_filer/services/publish_event.py b/queue_services/business-filer/src/business_filer/services/publish_event.py
index b95b1ba804..824045e094 100644
--- a/queue_services/business-filer/src/business_filer/services/publish_event.py
+++ b/queue_services/business-filer/src/business_filer/services/publish_event.py
@@ -1,8 +1,9 @@
+import re
 import uuid
 from datetime import UTC, datetime
 
 # if TYPE_CHECKING:
-from business_model.models import Business, Filing
+from business_model.models import Business, Document, Filing
 from flask import Flask
 
 from business_filer.common.filing import FilingTypes
@@ -10,6 +11,10 @@
 from business_filer.services import Flags, gcp_queue
 from gcp_queue import SimpleCloudEvent, to_queue_message
 
+# DRS keys are formatted as "{documentClass}-{documentServiceId}", e.g. "COOP-DS0000101951".
+# Legacy Minio keys (UUIDs) do not match this pattern.
+_DRS_KEY_PATTERN = re.compile(r"^[A-Z]+-DS\d+$")
+
 
 class PublishEvent:
     """Service to publish specific events onto the GCP Queue."""
@@ -78,6 +83,39 @@ def publish_drs_create_message(app: Flask, business: Business, filing: Filing):
         except Exception as err:  # pylint: disable=broad-except;
             raise PublishException(err) from err
 
+    @staticmethod
+    def publish_drs_update_message(app: Flask, business: Business, filing: Filing):
+        """Publish a drs update record message for each DRS document uploaded with the filing.
+
+        Updates the document record(s) with filing/business information once a filing completes,
+        so the document shows up correctly in the ledger and is searchable in the DRS UI.
+        """
+        try:
+            subject = app.config.get("DOC_UPDATE_REC_TOPIC")
+            documents = Document.query.filter_by(filing_id=filing.id).all()
+            for document in documents:
+                if not PublishEvent._is_drs_document(document.file_key):
+                    continue
+                data = {
+                    "accountId": "business-api",
+                    "fileKey": document.file_key,
+                    "businessIdentifier": business.identifier if business else None,
+                    "filingDate": filing.completion_date.isoformat() if filing.completion_date else None,
+                    "filingId": filing.id
+                }
+                data = {k: v for k, v in data.items() if v is not None}
+
+                ce = PublishEvent._create_cloud_event(app, business, filing, subject, data)
+                gcp_queue.publish(subject, to_queue_message(ce))
+
+        except Exception as err:  # pylint: disable=broad-except;
+            raise PublishException(err) from err
+
+    @staticmethod
+    def _is_drs_document(file_key: str) -> bool:
+        """Return True if the file_key is a DRS key."""
+        return bool(file_key) and bool(_DRS_KEY_PATTERN.match(file_key))
+
     @staticmethod
     def publish_mras_email(app: Flask, business: Business, filing: Filing):
         """Publish MRAS email message onto the NATS emailer subject."""
diff --git a/queue_services/business-filer/tests/unit/filing_processors/filing_components/test_document_records.py b/queue_services/business-filer/tests/unit/filing_processors/filing_components/test_document_records.py
deleted file mode 100644
index 94128b36b7..0000000000
--- a/queue_services/business-filer/tests/unit/filing_processors/filing_components/test_document_records.py
+++ /dev/null
@@ -1,129 +0,0 @@
-# Copyright © 2026 Province of British Columbia
-#
-# Licensed under the BSD 3 Clause License, (the "License");
-# you may not use this file except in compliance with the License.
-# The template for the license can be found here
-#    https://opensource.org/license/bsd-3-clause/
-#
-# Redistribution and use in source and binary forms,
-# with or without modification, are permitted provided that the
-# following conditions are met:
-#
-# 1. Redistributions of source code must retain the above copyright notice,
-#    this list of conditions and the following disclaimer.
-#
-# 2. Redistributions in binary form must reproduce the above copyright notice,
-#    this list of conditions and the following disclaimer in the documentation
-#    and/or other materials provided with the distribution.
-#
-# 3. Neither the name of the copyright holder nor the names of its contributors
-#    may be used to endorse or promote products derived from this software
-#    without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
-# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
-# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
-# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
-# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
-# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
-# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
-# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
-# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
-# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
-# POSSIBILITY OF SUCH DAMAGE.
-"""Unit tests for document_records filing component processor."""
-
-from unittest.mock import Mock, patch
-
-from business_model.models import Business, Document, Filing
-
-from business_filer.filing_processors.filing_components import document_records
-
-
-def test_skip_when_no_documents():
-    """Assert nothing happens when no documents exist."""
-
-    business = Business(identifier="BC1234567")
-    filing = Filing(id=1)
-
-    mock_query = Mock()
-    mock_query.filter_by.return_value.all.return_value = []
-
-    with patch.object(Document, "query", mock_query), \
-         patch.object(document_records.document_service, "update_document_record") as mock_update:
-
-        document_records.update_document_records(business, filing)
-
-        mock_update.assert_not_called()
-
-
-def test_updates_drs_document():
-    """Assert DRS documents are updated."""
-
-    business = Business(identifier="BC1234567")
-
-    filing = Filing(id=1)
-    filing._completion_date = None
-
-    document = Document(
-        id=10,
-        filing_id=1,
-        file_key="COOP-DS0000001234"
-    )
-
-    mock_query = Mock()
-    mock_query.filter_by.return_value.all.return_value = [document]
-
-    response = Mock()
-    response.ok = True
-
-    with patch.object(Document, "query", mock_query), \
-         patch.object(document_records.document_service,
-                      "update_document_record",
-                      return_value=response) as mock_update:
-
-        document_records.update_document_records(business, filing)
-
-        mock_update.assert_called_once()
-
-        args = mock_update.call_args[0]
-
-        assert args[0] == "COOP-DS0000001234"
-        assert args[1]["filingId"] == 1
-        assert args[1]["businessIdentifier"] == "BC1234567"
-
-
-def test_skip_legacy_document():
-    """Assert legacy Minio documents are ignored."""
-
-    business = Business(identifier="BC1234567")
-    filing = Filing(id=1)
-
-    document = Document(
-        id=10,
-        filing_id=1,
-        file_key="550e8400-e29b-41d4-a716-446655440000"
-    )
-
-    mock_query = Mock()
-    mock_query.filter_by.return_value.all.return_value = [document]
-
-    with patch.object(Document, "query", mock_query), \
-         patch.object(document_records.document_service,
-                      "update_document_record") as mock_update:
-
-        document_records.update_document_records(business, filing)
-
-        mock_update.assert_not_called()
-
-
-def test_is_drs_document():
-    """Assert DRS document detection."""
-    assert document_records._is_drs_document("COOP-DS0000123456")
-    assert document_records._is_drs_document("BEN-DS123456")
-
-    assert not document_records._is_drs_document(
-        "550e8400-e29b-41d4-a716-446655440000"
-    )
-    assert not document_records._is_drs_document("")
-    assert not document_records._is_drs_document(None)
diff --git a/queue_services/business-filer/tests/unit/test_publish/test_publish_drs_update.py b/queue_services/business-filer/tests/unit/test_publish/test_publish_drs_update.py
new file mode 100644
index 0000000000..ddb9023de7
--- /dev/null
+++ b/queue_services/business-filer/tests/unit/test_publish/test_publish_drs_update.py
@@ -0,0 +1,190 @@
+# Copyright © 2026 Province of British Columbia
+#
+# Licensed under the BSD 3 Clause License, (the "License");
+# you may not use this file except in compliance with the License.
+# The template for the license can be found here
+#    https://opensource.org/license/bsd-3-clause/
+#
+# Redistribution and use in source and binary forms,
+# with or without modification, are permitted provided that the
+# following conditions are met:
+#
+# 1. Redistributions of source code must retain the above copyright notice,
+#    this list of conditions and the following disclaimer.
+#
+# 2. Redistributions in binary form must reproduce the above copyright notice,
+#    this list of conditions and the following disclaimer in the documentation
+#    and/or other materials provided with the distribution.
+#
+# 3. Neither the name of the copyright holder nor the names of its contributors
+#    may be used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS “AS IS”
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+# THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+# ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+# LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+# CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+# SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+# INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+# CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+# ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+"""Unit tests for PublishEvent.publish_drs_update_message."""
+import json
+from datetime import UTC, datetime
+from unittest.mock import Mock, patch
+
+from business_model.models import Business, Document, Filing
+
+from business_filer.services import gcp_queue
+from business_filer.services.publish_event import PublishEvent
+
+IDENTIFIER = 'BC1234567'
+FILING_ID = 1438352
+COMPLETION_DATE = '2026-06-09T23:02:02+00:00'
+FILE_KEY_1 = 'COOP-DS0000101951'
+FILE_KEY_2 = 'BEN-DS0000101952'
+
+def _make_minimal_filing():
+    filing = Filing()
+    filing.id = FILING_ID
+    filing._filing_type = 'continuationIn'
+    filing._completion_date = datetime.fromisoformat(COMPLETION_DATE)
+    return filing
+
+
+def test_publish_drs_update_no_documents(app):
+    """Assert nothing is published when the filing has no documents."""
+    business = Business(identifier=IDENTIFIER)
+    filing = _make_minimal_filing()
+
+    mock_query = Mock()
+    mock_query.filter_by.return_value.all.return_value = []
+
+    with patch.object(Document, 'query', mock_query), \
+         patch.object(gcp_queue, 'publish') as mock_publish:
+
+        PublishEvent.publish_drs_update_message(app, business, filing)
+
+        mock_publish.assert_not_called()
+
+
+def test_publish_drs_update_drs_document(app):
+    """Assert a drs update message is published for a DRS document."""
+    business = Business(identifier=IDENTIFIER)
+    filing = _make_minimal_filing()
+
+    document = Document(
+        id=10,
+        filing_id=filing.id,
+        file_key=FILE_KEY_1
+    )
+
+    mock_query = Mock()
+    mock_query.filter_by.return_value.all.return_value = [document]
+
+    with patch.object(Document, 'query', mock_query), \
+         patch.object(gcp_queue, 'publish') as mock_publish:
+
+        PublishEvent.publish_drs_update_message(app, business, filing)
+
+        mock_publish.assert_called_once()
+        subject, payload = mock_publish.call_args.args
+        assert subject == app.config['DOC_UPDATE_REC_TOPIC']
+        payload_data = (json.loads(payload)).get('data')
+        assert payload_data == {
+            'accountId': 'business-api',
+            'fileKey': FILE_KEY_1,
+            'businessIdentifier': IDENTIFIER,
+            'filingDate': COMPLETION_DATE,
+            'filingId': FILING_ID
+        }
+
+
+def test_publish_drs_update_multiple_documents(app):
+    """Assert one message is published per DRS document, skipping legacy keys."""
+    business = Business(identifier=IDENTIFIER)
+    filing = _make_minimal_filing()
+
+    documents = [
+        Document(id=10, filing_id=filing.id, file_key=FILE_KEY_1),
+        Document(id=11, filing_id=filing.id, file_key='550e8400-e29b-41d4-a716-446655440000'),
+        Document(id=12, filing_id=filing.id, file_key=FILE_KEY_2),
+    ]
+
+    mock_query = Mock()
+    mock_query.filter_by.return_value.all.return_value = documents
+
+    with patch.object(Document, 'query', mock_query), \
+         patch.object(gcp_queue, 'publish') as mock_publish:
+
+        PublishEvent.publish_drs_update_message(app, business, filing)
+
+        assert mock_publish.call_count == 2
+        file_keys = [
+            (json.loads(call.args[1])).get('data', {}).get('fileKey')
+            for call in mock_publish.call_args_list
+        ]
+        assert file_keys == [FILE_KEY_1, FILE_KEY_2]
+
+
+def test_publish_drs_update_skip_legacy_document(app):
+    """Assert legacy Minio documents are ignored."""
+    business = Business(identifier=IDENTIFIER)
+    filing = _make_minimal_filing()
+
+    document = Document(
+        id=10,
+        filing_id=filing.id,
+        file_key='550e8400-e29b-41d4-a716-446655440000'
+    )
+
+    mock_query = Mock()
+    mock_query.filter_by.return_value.all.return_value = [document]
+
+    with patch.object(Document, 'query', mock_query), \
+         patch.object(gcp_queue, 'publish') as mock_publish:
+
+        PublishEvent.publish_drs_update_message(app, business, filing)
+
+        mock_publish.assert_not_called()
+
+
+def test_publish_drs_update_omits_empty_values(app):
+    """Assert filingDate is omitted when the filing has no completion date."""
+    business = Business(identifier=IDENTIFIER)
+    filing = _make_minimal_filing()
+    filing._completion_date = None
+
+    document = Document(
+        id=10,
+        filing_id=filing.id,
+        file_key=FILE_KEY_1
+    )
+
+    mock_query = Mock()
+    mock_query.filter_by.return_value.all.return_value = [document]
+
+    with patch.object(Document, 'query', mock_query), \
+         patch.object(gcp_queue, 'publish') as mock_publish:
+
+        PublishEvent.publish_drs_update_message(app, business, filing)
+
+        mock_publish.assert_called_once()
+        payload_data = (json.loads(mock_publish.call_args.args[1])).get('data')
+        assert 'filingDate' not in payload_data
+        assert payload_data.get('filingId') == FILING_ID
+
+
+def test_is_drs_document():
+    """Assert DRS document detection."""
+    assert PublishEvent._is_drs_document(FILE_KEY_1)
+    assert PublishEvent._is_drs_document(FILE_KEY_2)
+    assert PublishEvent._is_drs_document('COOP-DS0000123456')
+    assert PublishEvent._is_drs_document('BEN-DS123456')
+
+    assert not PublishEvent._is_drs_document('550e8400-e29b-41d4-a716-446655440000')
+    assert not PublishEvent._is_drs_document('')
+    assert not PublishEvent._is_drs_document(None)