diff --git a/src/openforms/registrations/contrib/stuf_zds/tests/test_backend.py b/src/openforms/registrations/contrib/stuf_zds/tests/test_backend.py
index 9d3c6fb15f..902505e06d 100644
--- a/src/openforms/registrations/contrib/stuf_zds/tests/test_backend.py
+++ b/src/openforms/registrations/contrib/stuf_zds/tests/test_backend.py
@@ -2806,3 +2806,72 @@ def test_user_defined_variables(self, m, mock_task):
             "//stuf:extraElementen/stuf:extraElement[@naam='userDefinedVarJson.key2.0']",
             "value2",
         )
+
+    @patch("celery.app.task.Task.request")
+    def test_plugin_with_extra_unmapped_number_data(self, m, mock_task):
+        submission = SubmissionFactory.from_components(
+            [
+                {
+                    "key": "extra_number",
+                },
+            ],
+            form__name="my-form",
+            bsn="111222333",
+            public_registration_reference="foo-zaak",
+            registration_result={"intermediate": {"zaaknummer": "foo-zaak"}},
+            submitted_data={"extra_number": 2023},
+            language_code="en",
+        )
+
+        m.post(
+            self.service.soap_service.url,
+            content=load_mock("creeerZaak.xml"),
+            additional_matcher=match_text("zakLk01"),
+        )
+
+        m.post(
+            self.service.soap_service.url,
+            content=load_mock(
+                "genereerDocumentIdentificatie.xml",
+                {"document_identificatie": "bar-document"},
+            ),
+            additional_matcher=match_text("genereerDocumentIdentificatie_Di02"),
+        )
+
+        m.post(
+            self.service.soap_service.url,
+            content=load_mock("voegZaakdocumentToe.xml"),
+            additional_matcher=match_text("edcLk01"),
+        )
+        mock_task.id = 1
+
+        form_options = {
+            "zds_zaaktype_code": "zt-code",
+            "zds_zaaktype_omschrijving": "zt-omschrijving",
+            "zds_zaaktype_status_code": "123",
+            "zds_zaaktype_status_omschrijving": "aaabbc",
+            "zds_documenttype_omschrijving_inzending": "aaabbc",
+        }
+
+        plugin = StufZDSRegistration("stuf")
+        serializer = plugin.configuration_options(data=form_options)
+        self.assertTrue(serializer.is_valid())
+
+        result = plugin.register_submission(submission, serializer.validated_data)
+        self.assertEqual(
+            result,
+            {
+                "zaak": "foo-zaak",
+                "document": "bar-document",
+            },
+        )
+
+        xml_doc = xml_from_request_history(m, 0)
+        self.assertSoapXMLCommon(xml_doc)
+
+        # extraElementen
+        self.assertXPathEquals(
+            xml_doc,
+            "//stuf:extraElementen/stuf:extraElement[@naam='extra_number']",
+            "2023",
+        )
diff --git a/src/stuf/stuf_zds/templates/stuf_zds/soap/creeerZaak.xml b/src/stuf/stuf_zds/templates/stuf_zds/soap/creeerZaak.xml
index 2d620159e5..153c4e5847 100644
--- a/src/stuf/stuf_zds/templates/stuf_zds/soap/creeerZaak.xml
+++ b/src/stuf/stuf_zds/templates/stuf_zds/soap/creeerZaak.xml
@@ -1,4 +1,4 @@
-{% extends "stuf/soap_envelope.xml" %}{% load stuf l10n %}
+{% extends "stuf/soap_envelope.xml" %}{% load stuf %}
 {% block body %}
 {# Parent template already defines some common namespaces #}
 <ZKN:zakLk01
@@ -31,7 +31,7 @@
                <ZKN:omschrijving>{{ locatie.key }}</ZKN:omschrijving>
                <ZKN:lokatie>
                     <GML:Point srsName="http://www.opengis.net/def/crs/EPSG/0/4326">
-                        <GML:pos>{{ locatie.lat|unlocalize }} {{ locatie.lng|unlocalize }}</GML:pos>
+                        <GML:pos>{{ locatie.lat }} {{ locatie.lng }}</GML:pos>
                     </GML:Point>
                </ZKN:lokatie>
         </ZKN:anderZaakObject>
diff --git a/src/stuf/templates/stuf/soap_envelope.xml b/src/stuf/templates/stuf/soap_envelope.xml
index 9d1aced88d..81c265481c 100644
--- a/src/stuf/templates/stuf/soap_envelope.xml
+++ b/src/stuf/templates/stuf/soap_envelope.xml
@@ -1,4 +1,4 @@
-{% load stuf %}<?xml version="1.0" encoding="UTF-8"?>
+{% load stuf l10n %}<?xml version="1.0" encoding="UTF-8"?>
 <soapenv:Envelope
     xmlns:soapenv="{% if soap_version == '1.1' %}http://schemas.xmlsoap.org/soap/envelope/{% else %}http://www.w3.org/2003/05/soap-envelope{% endif %}"
     xmlns:StUF="http://www.egem.nl/StUF/StUF0301"
@@ -8,6 +8,6 @@
         {% render_security service security_expires_minutes %}
     </soapenv:Header>
     <soapenv:Body>
-        {% block body %}{% endblock %}
+        {% localize off %}{% block body %}{% endblock %}{% endlocalize %}
     </soapenv:Body>
 </soapenv:Envelope>