diff --git a/src/openforms/appointments/renderer.py b/src/openforms/appointments/renderer.py
index 8ffd9e5402..b71f2c3d94 100644
--- a/src/openforms/appointments/renderer.py
+++ b/src/openforms/appointments/renderer.py
@@ -45,8 +45,9 @@ def __str__(self) -> SafeString:
         )
         plugin = get_plugin(plugin=appointment.plugin)
 
+        identifier: str = self.submission.appointment_info.appointment_id
         ctx = {
-            "appointment": plugin.get_appointment_details(appointment.pk),
+            "appointment": plugin.get_appointment_details(identifier),
             "contact_details": self.get_children(),  # todo: a bit of a wart
         }
         return render_to_string(template_name, ctx)
diff --git a/src/openforms/appointments/tests/test_pdf.py b/src/openforms/appointments/tests/test_pdf.py
index 5a70234374..a3043ce7b5 100644
--- a/src/openforms/appointments/tests/test_pdf.py
+++ b/src/openforms/appointments/tests/test_pdf.py
@@ -1,10 +1,13 @@
-from django.test import RequestFactory, TestCase, override_settings
+from unittest.mock import patch
+
+from django.test import RequestFactory, TestCase, override_settings, tag
 from django.utils.html import escape
 
 from openforms.accounts.tests.factories import SuperUserFactory
 from openforms.submissions.dev_views import SubmissionPDFTestView
 from openforms.submissions.tests.factories import SubmissionFactory
 
+from ..contrib.demo.plugin import DemoAppointment
 from .factories import AppointmentFactory, AppointmentProductFactory
 
 
@@ -18,6 +21,7 @@ def setUpTestData(cls):
             submission__registration_success=True,
             submission__with_report=True,
             appointment_info__registration_ok=True,
+            appointment_info__appointment_id="a-remote-id",
             location__identifier="1",
         )
         AppointmentProductFactory.create(
@@ -59,3 +63,17 @@ def test_submission_without_appointment_shows_no_appointment_info(self):
         html = submission.report.generate_submission_report_pdf()
 
         self.assertNotIn("Afspraakinformatie", html)
+
+    @tag("gh-4103")
+    def test_uses_remote_appoinment_id(self):
+        plugin = DemoAppointment("demo")
+
+        with (
+            patch("openforms.appointments.renderer.get_plugin", return_value=plugin),
+            patch.object(
+                plugin, "get_appointment_details", wraps=plugin.get_appointment_details
+            ) as m_get_details,
+        ):
+            self.submission.report.generate_submission_report_pdf()
+
+        m_get_details.assert_called_once_with("a-remote-id")