diff --git a/.gitea/workflows/ci.yaml b/.gitea/workflows/ci.yaml
index 7eabeb2..ca47c29 100644
--- a/.gitea/workflows/ci.yaml
+++ b/.gitea/workflows/ci.yaml
@@ -207,6 +207,9 @@ jobs:
       - name: Objecten API up + token authenticates + trusts Objecttypen
         id: objecten
         run: OBJECTEN_TIMEOUT=120 make verify-objecten
+      - name: RegisterRecord objecttype registered + published
+        id: registerrecord
+        run: REGISTERRECORD_TIMEOUT=120 make verify-registerrecord
       - name: ACL ↔ OpenZaak integration tests
         id: acl
         run: make verify-acl
@@ -241,6 +244,7 @@ jobs:
           OBS: ${{ steps.obs.outcome }}
           OBJECTTYPEN: ${{ steps.objecttypen.outcome }}
           OBJECTEN: ${{ steps.objecten.outcome }}
+          REGISTERRECORD: ${{ steps.registerrecord.outcome }}
           ACL: ${{ steps.acl.outcome }}
           NRC: ${{ steps.nrc.outcome }}
           PROJECTION: ${{ steps.projection.outcome }}
@@ -261,6 +265,7 @@ jobs:
             echo "| Observability backplane | $(icon "$OBS") |"
             echo "| Objecttypen API + token | $(icon "$OBJECTTYPEN") |"
             echo "| Objecten API + token | $(icon "$OBJECTEN") |"
+            echo "| RegisterRecord objecttype | $(icon "$REGISTERRECORD") |"
             echo "| ACL ↔ OpenZaak | $(icon "$ACL") |"
             echo "| OpenZaak → NRC | $(icon "$NRC") |"
             echo "| NRC → Event Subscriber → projection | $(icon "$PROJECTION") |"
diff --git a/Makefile b/Makefile
index a399cbf..2b7199f 100644
--- a/Makefile
+++ b/Makefile
@@ -43,7 +43,7 @@ export DOCKER_HOST := unix://$(PODMAN_SOCK)
 endif
 endif
 
-.PHONY: ci lint build unit mutation frontend integration verify verify-up verify-acl verify-nrc verify-projection verify-bff verify-domain verify-observability verify-tracing verify-metrics verify-objecttypen verify-objecten verify-notifications smoke up down local verify-local local-down changelog openzaak-up openzaak-smoke openzaak-seed openzaak-down stack-up stack-smoke stack-down keycloak-up keycloak-smoke keycloak-down flowable-up flowable-smoke flowable-down help
+.PHONY: ci lint build unit mutation frontend integration verify verify-up verify-acl verify-nrc verify-projection verify-bff verify-domain verify-observability verify-tracing verify-metrics verify-objecttypen verify-objecten verify-registerrecord verify-notifications smoke up down local verify-local local-down changelog openzaak-up openzaak-smoke openzaak-seed openzaak-down stack-up stack-smoke stack-down keycloak-up keycloak-smoke keycloak-down flowable-up flowable-smoke flowable-down help
 
 ## ci: run the full pipeline — lint, build, unit, mutation, frontend, verify (mirrors Gitea Actions)
 ## `verify` is the live-stack stage (full stack up once → ACL + notification checks).
@@ -196,6 +196,11 @@ verify-objecttypen:
 verify-objecten:
 	bash infra/run-objecten-check.sh
 
+## verify-registerrecord: assert the RegisterRecord objecttype is registered + published in the
+## Objecttypen API (S-18c), against the already-running stack.
+verify-registerrecord:
+	bash infra/run-registerrecord-check.sh
+
 ## verify: local mirror of the CI verify-stack job — full stack up once, all checks,
 ## tear down (always). For fast single-concern local iteration use `integration`
 ## (oz-only) or `verify-notifications` (oz+nrc) instead.
diff --git a/infra/registerrecord-check.py b/infra/registerrecord-check.py
new file mode 100644
index 0000000..6e02dca
--- /dev/null
+++ b/infra/registerrecord-check.py
@@ -0,0 +1,66 @@
+#!/usr/bin/env python3
+"""S-18c (#141): prove the RegisterRecord objecttype is registered + published in the Objecttypen API.
+
+Assert the objecttype named "RegisterRecord" exists, has a **published** version, and that version's
+jsonSchema carries the public-safe fields (id, status, reference) — i.e. registerrecord-init ran and
+seeded the schema S-19 will write records against. Stdlib only so it runs in a bare python:3-slim
+container on the compose network.
+"""
+import json
+import os
+import sys
+import time
+import urllib.error
+import urllib.request
+
+BASE = os.environ["OBJECTTYPEN"]          # http://<ip>:8000
+TOKEN = os.environ["OBJECTTYPEN_TOKEN"]
+TIMEOUT = int(os.environ.get("REGISTERRECORD_TIMEOUT", "60"))
+NAME = "RegisterRecord"
+EXPECTED_FIELDS = {"id", "status", "reference"}
+
+
+def get(path):
+    req = urllib.request.Request(f"{BASE}{path}", headers={"Authorization": f"Token {TOKEN}"})
+    with urllib.request.urlopen(req, timeout=10) as r:
+        return json.load(r)
+
+
+def check():
+    """Return (ok, detail). Raises on transport errors so the caller can retry."""
+    ots = get("/api/v2/objecttypes").get("results", [])
+    match = next((o for o in ots if o.get("name") == NAME), None)
+    if not match:
+        return False, f"no objecttype named {NAME!r} (have: {[o.get('name') for o in ots]})"
+    if not match.get("versions"):
+        return False, f"{NAME} exists but has no versions"
+    # The versions list holds URLs; fetch each to find a published one.
+    for ver_url in match["versions"]:
+        ver = get(ver_url[len(BASE):] if ver_url.startswith(BASE) else ver_url)
+        if ver.get("status") != "published":
+            continue
+        props = set((ver.get("jsonSchema") or {}).get("properties", {}))
+        if not EXPECTED_FIELDS <= props:
+            return False, f"published version missing fields: {EXPECTED_FIELDS - props}"
+        return True, f"{NAME} v{ver.get('version')} published, fields={sorted(props)}"
+    return False, f"{NAME} has versions but none are published"
+
+
+def main():
+    deadline = time.time() + TIMEOUT
+    detail = "no attempt"
+    while time.time() < deadline:
+        try:
+            ok, detail = check()
+            if ok:
+                print(f"OK — {detail}")
+                return 0
+        except (urllib.error.URLError, ConnectionError, TimeoutError) as e:
+            detail = f"transport: {e}"
+        time.sleep(3)
+    print(f"FAIL — {detail}", file=sys.stderr)
+    return 1
+
+
+if __name__ == "__main__":
+    sys.exit(main())
diff --git a/infra/run-registerrecord-check.sh b/infra/run-registerrecord-check.sh
new file mode 100755
index 0000000..3f4d546
--- /dev/null
+++ b/infra/run-registerrecord-check.sh
@@ -0,0 +1,28 @@
+#!/usr/bin/env bash
+#
+# S-18c (#141): assert the RegisterRecord objecttype is registered + published in the Objecttypen
+# API, against an ALREADY-RUNNING stack. Runs the check in a python:3-slim container on the stack
+# network (the service is reached by container IP; the runner can't reach published ports —
+# gitea-actions-gotchas.md §5/§6). Does NOT manage the stack lifecycle.
+set -euo pipefail
+
+here="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+
+# The dev token provisioned by infra/objecttypen/setup_configuration/data.yaml.
+TOKEN="${OBJECTTYPEN_TOKEN:-0123456789abcdef0123456789abcdef01234567}"
+
+ot="$(docker ps -q --filter 'name=objecttypen' --filter 'health=healthy' | head -1)"
+[ -n "$ot" ] || ot="$(docker ps -q --filter 'name=[-_]objecttypen[-_]' | head -1)"
+[ -n "$ot" ] || { echo "ERROR: no running objecttypen container — bring the stack up first" >&2; exit 1; }
+net="$(docker inspect -f '{{range $k,$_ := .NetworkSettings.Networks}}{{$k}}{{"\n"}}{{end}}' "$ot" | head -1)"
+ip="$(docker inspect -f '{{range .NetworkSettings.Networks}}{{.IPAddress}}{{end}}' "$ot")"
+echo ">> network=$net objecttypen=$ip"
+
+cid="$(docker create --network "$net" \
+  -e "OBJECTTYPEN=http://$ip:8000" -e "OBJECTTYPEN_TOKEN=$TOKEN" \
+  -e "REGISTERRECORD_TIMEOUT=${REGISTERRECORD_TIMEOUT:-60}" \
+  python:3-slim python /registerrecord-check.py)"
+docker cp "$here/registerrecord-check.py" "$cid:/registerrecord-check.py" >/dev/null
+rc=0; docker start -a "$cid" || rc=$?
+docker rm -f "$cid" >/dev/null
+exit $rc