diff --git a/.github/workflows/job-report-expiry-undeliverable-test-run.yml b/.github/workflows/job-report-expiry-undeliverable-test-run.yml
new file mode 100644
index 000000000..2c36c1435
--- /dev/null
+++ b/.github/workflows/job-report-expiry-undeliverable-test-run.yml
@@ -0,0 +1,30 @@
+name: Certificate Expiry Undeliverable Report Test Run
+
+on:
+  workflow_dispatch:
+    inputs:
+      email:
+        description: What is the email address of the recipient?
+jobs:
+  certificate-expiry-check:
+    name: Run certificate expiry undeliverable report script
+    runs-on: ubuntu-latest
+    permissions:
+      id-token: write
+      contents: read
+    steps:
+      - name: checkout repo content
+        uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - name: Python Setup
+        uses: actions/setup-python@0b93645e9fea7318ecaed2b359559ac225c90a2b # v5.3.0
+        with:
+          python-version: '3.11'
+      - name: Install Python Packages from Requirements File
+        run: |
+          pip install pipenv
+          pipenv install
+      - name: Execute certificate expiry undeliverable report run
+        run: pipenv run python3 -m bin.report_certificate_expiry_undeliverable --test ${{ github.event.inputs.email }}
+        env:
+          NOTIFY_PROD_API_KEY: ${{ secrets.NOTIFY_PROD_API_KEY }}
+          
\ No newline at end of file
diff --git a/bin/check_certificate_expiry.py b/bin/check_certificate_expiry.py
index 8151c13a6..762917ba6 100644
--- a/bin/check_certificate_expiry.py
+++ b/bin/check_certificate_expiry.py
@@ -20,7 +20,6 @@
     "CERT_EXPIRY_THRESHOLDS": [30],
     "CERT_URL_EXTENSION": "v5/certificate/issued-certs",
     "CERT_REPORT_TEMPLATE_ID": "04b6ca6c-2945-4a0d-a267-53fb61b370ef",
-    "CERT_EXPIRY_TEMPALATE_ID": "06abd028-0a8f-43d9-a122-90a92f9b62ee"
 }
 
 
diff --git a/bin/report_certificate_expiry_undeliverable.py b/bin/report_certificate_expiry_undeliverable.py
new file mode 100644
index 000000000..55fe18fe3
--- /dev/null
+++ b/bin/report_certificate_expiry_undeliverable.py
@@ -0,0 +1,65 @@
+import os
+import sys
+import logging
+
+from services.notify_service import NotifyService
+
+from config.constants import MINISTRY_OF_JUSTICE
+
+logging.basicConfig(
+    level=logging.INFO, format="%(asctime)s - %(name)s - %(levelname)s - %(message)s"
+)
+logger = logging.getLogger(__name__)
+
+
+cert_config = {
+    "CERT_REPLY_EMAIL": "certificates@digital.justice.gov.uk",
+    "CERT_EXPIRY_TEMPALATE_ID": "06abd028-0a8f-43d9-a122-90a92f9b62ee",
+    "CERT_UNDELIVERED_REPORT_TEMPALATE_ID": "6d0e7249-6b2d-4f0e-bf32-657e9300d09e"
+}
+
+
+def get_environment_variables():
+
+    notify_api_key = os.environ.get("NOTIFY_PROD_API_KEY")
+    if not notify_api_key:
+        raise ValueError("No NOTIFY_PROD_API_KEY environment variable set")
+
+    return notify_api_key
+
+
+def main(testrun: bool = False, test_email: str = ""):
+
+    notify_api_key = get_environment_variables()
+
+    logger.info("Instantiating services...")
+    notify_service = NotifyService(cert_config, notify_api_key, MINISTRY_OF_JUSTICE)
+
+    print("Building undelivered email report...")
+    if undelivered_email_report := notify_service.check_for_undelivered_emails_for_template(
+        cert_config["CERT_EXPIRY_TEMPALATE_ID"]
+    ):
+        if testrun:
+            logger.info("Building undelivered email report...")
+            report = notify_service.build_undeliverable_email_report_string_crs(
+                undelivered_email_report)
+            logger.info("Sending test undelivered email test report to %s...", test_email)
+            notify_service.send_report_email_crs(
+                report, cert_config['CERT_UNDELIVERED_REPORT_TEMPALATE_ID'], test_email)
+        else:
+            logger.info("Building undelivered email live report...")
+            report = notify_service.build_undeliverable_email_report_string_crs(
+                    undelivered_email_report)
+            logger.info("Sending live undelivered emailreport to Operations Engineering...")
+            notify_service.send_report_email_crs(
+                report, cert_config["CERT_UNDELIVERED_REPORT_TEMPALATE_ID"], cert_config["CERT_REPLY_EMAIL"])
+
+
+if __name__ == "__main__":
+    if len(sys.argv) > 1 and sys.argv[1] == '--test':
+        if len(sys.argv) > 2:
+            main(True, sys.argv[2])
+        else:
+            raise SystemExit('Email address of recipient expected.')
+    else:
+        main()
diff --git a/services/notify_service.py b/services/notify_service.py
index f35bf3198..11540ac2a 100644
--- a/services/notify_service.py
+++ b/services/notify_service.py
@@ -65,13 +65,13 @@ def send_removed_email(self, email_address: str):
         )
 
     def check_for_undelivered_first_emails(self):
-        return self._check_for_undelivered_emails_for_template(
+        return self.check_for_undelivered_emails_for_template(
             self._get_first_email_template_id())
 
     def _get_notifications_by_type_and_status(self, template_type, status):
         return self.client.get_all_notifications(status=status, template_type=template_type)
 
-    def _check_for_undelivered_emails_for_template(self, template_id):
+    def check_for_undelivered_emails_for_template(self, template_id):
         notifications = self._get_notifications_by_type_and_status('email', 'failed')[
             'notifications']
         today = datetime.now(timezone.utc).date()
@@ -158,6 +158,14 @@ def build_main_report_string_crs(self, email_parameter_list):
             for email_parameter in email_parameter_list
         )
 
+    def build_undeliverable_email_report_string_crs(self, undeliverable_email_list):
+        return "".join(
+            f"Email Address: {undeliverable_email['email_address']}\n"
+            f"Sent at: {undeliverable_email['created_at']}\n"
+            f"Status: {undeliverable_email['status']} \n\n"
+            for undeliverable_email in undeliverable_email_list
+        )
+
     def send_report_email_crs(self, report, template_id, email):
         try:
             self.client.send_email_notification(
diff --git a/test/test_services/test_notify_service.py b/test/test_services/test_notify_service.py
index e6ef12267..b93265ee2 100644
--- a/test/test_services/test_notify_service.py
+++ b/test/test_services/test_notify_service.py
@@ -27,7 +27,7 @@ def test_undelivered_emails_not_found_returns_none(self, mock_get_notifications_
             "notifications": []
         }
 
-        result = self.notify_service._check_for_undelivered_emails_for_template(
+        result = self.notify_service.check_for_undelivered_emails_for_template(
             self.template_id)
         self.assertEqual(len(result), 0)
 
@@ -45,7 +45,7 @@ def test_undelivered_emails_found_returns_expected_data(self, mock_get_notificat
             ]
         }
 
-        result = self.notify_service._check_for_undelivered_emails_for_template(
+        result = self.notify_service.check_for_undelivered_emails_for_template(
             self.template_id)
 
         self.assertEqual(len(result), 1)
@@ -201,7 +201,7 @@ def test_get_first_email_template_id_moj_org(self):
         self.assertEqual(self.notify_service._get_first_email_template_id(
         ), "30351e8f-320b-4ebe-b0bf-d6aa0a7c607d")
 
-    @patch.object(NotifyService, "_check_for_undelivered_emails_for_template")
+    @patch.object(NotifyService, "check_for_undelivered_emails_for_template")
     @patch.object(NotifyService, "_get_first_email_template_id")
     def test_check_for_undelivered_first_emails(self, mock_get_first_email_template_id, mock_check_for_undelivered_emails_for_template):
         mock_check_for_undelivered_emails_for_template.return_value = "some-value"