diff --git a/infra/run-domain-check.sh b/infra/run-domain-check.sh
index ef9f95d..409ea76 100755
--- a/infra/run-domain-check.sh
+++ b/infra/run-domain-check.sh
@@ -158,6 +158,49 @@ done
 [ -n "$gone" ] || { echo "FAIL — Beoordelen task for $reg_id2 still active after withdrawal" >&2; docker logs "$dom" 2>&1 | tail -15 >&2; exit 1; }
 echo "OK — withdrawal cancelled the Beoordelen task; the registratie process ended (ingetrokken)"
 
+# ── S-13: diploma-eligibility routing. A registration with a FOREIGN diploma must route through the
+# extra CBGVAdvies user task before Beoordelen (the DMN businessRuleTask sets route=CBGV_ADVIES and the
+# gateway branches, ADR-0016). The domestic DIRECT path is already proven by the first registration
+# above, which parked straight at Beoordelen. ──────────────────────────────────────────────────────
+cbgv_query='{"processDefinitionKey":"registratie","taskDefinitionKey":"CBGVAdvies","includeProcessVariables":true}'
+echo ">> submitting a registration with a foreign diploma"
+locf="$(docker run --rm --network "$net" curlimages/curl:latest \
+  -fsS -D - -o /dev/null -X POST "http://$dom_ip:8080/registrations" \
+  -H 'Content-Type: application/json' -d '{"bsn":"123456782","diplomaOrigin":"Buitenlands"}' \
+  | sed -n 's/\r$//; s/^[Ll]ocation: //p' | head -1)"
+[ -n "$locf" ] || { echo "FAIL — foreign POST /registrations returned no Location" >&2; exit 1; }
+reg_idf="${locf##*/}"
+echo ">> foreign registration $reg_idf"
+
+echo ">> polling Flowable for its CBGV-advies task (foreign diplomas route here first)"
+cbgv_task=""
+for _ in $(seq 1 30); do
+  resp="$(flcurl -X POST "$fl_base/query/tasks" -H 'Content-Type: application/json' -d "$cbgv_query" 2>/dev/null || true)"
+  cbgv_task="$(printf '%s' "$resp" | task_for_reg "$reg_idf")"
+  [ -n "$cbgv_task" ] && break
+  sleep 2
+done
+[ -n "$cbgv_task" ] || { echo "FAIL — no CBGVAdvies task appeared for the foreign registration $reg_idf" >&2; docker logs "$dom" 2>&1 | tail -15 >&2; exit 1; }
+echo ">> CBGVAdvies task $cbgv_task is waiting"
+
+echo ">> asserting it has NOT reached Beoordelen yet (still awaiting CBGV-advies)"
+resp="$(flcurl -X POST "$fl_base/query/tasks" -H 'Content-Type: application/json' -d "$query")"
+early="$(printf '%s' "$resp" | task_for_reg "$reg_idf")"
+[ -z "$early" ] || { echo "FAIL — foreign registration reached Beoordelen ($early) before CBGV-advies" >&2; exit 1; }
+
+echo ">> completing the CBGV-advies task"
+flcurl -X POST "$fl_base/runtime/tasks/$cbgv_task" -H 'Content-Type: application/json' -d '{"action":"complete"}' >/dev/null
+
+echo ">> asserting it now advances to Beoordelen"
+onward=""
+for _ in $(seq 1 15); do
+  resp="$(flcurl -X POST "$fl_base/query/tasks" -H 'Content-Type: application/json' -d "$query" 2>/dev/null || true)"
+  [ -n "$(printf '%s' "$resp" | task_for_reg "$reg_idf")" ] && { onward=1; break; }
+  sleep 2
+done
+[ -n "$onward" ] || { echo "FAIL — foreign registration did not reach Beoordelen after CBGV-advies" >&2; exit 1; }
+echo "OK — foreign diploma routed through CBGV-advies, then on to Beoordelen (DMN + gateway)"
+
 # ── S-14: escalation. A third registration parks at Beoordelen. We fire its 14-day boundary timer
 # early via Flowable's management API (the timer job is moved to executable and run), which routes a
 # parallel token to the BeoordelingEscaleren external task. The domain's escalation worker acquires
diff --git a/tests/acceptance/Features/EenDiplomaRouteren.feature b/tests/acceptance/Features/EenDiplomaRouteren.feature
new file mode 100644
index 0000000..f404ab5
--- /dev/null
+++ b/tests/acceptance/Features/EenDiplomaRouteren.feature
@@ -0,0 +1,19 @@
+# language: en
+# Drives S-13 (#14). A registration's diploma origin decides its route: a domestic (Binnenlands)
+# diploma goes straight to beoordeling, a foreign (Buitenlands) one is routed through an extra
+# CBGV-advies step (PRD flow 4). The decision itself is a DMN evaluated inside the workflow
+# (ADR-0016); the domain's part — verified here — is carrying the origin into the process so the DMN
+# can route on it. The DMN evaluation and the CBGV routing are verified live (verify-domain).
+Feature: Een diploma op herkomst routeren
+  Als register wil ik een aanvraag met een buitenlands diploma extra laten toetsen
+  zodat een CBGV-advies wordt ingewonnen voordat een behandelaar beoordeelt.
+
+  Scenario: Een binnenlands diploma start de registratie als binnenlands
+    Given a zorgprofessional with a "Binnenlands" diploma
+    When they submit their registration
+    Then the registratie process is started carrying a "Binnenlands" diploma
+
+  Scenario: Een buitenlands diploma start de registratie als buitenlands
+    Given a zorgprofessional with a "Buitenlands" diploma
+    When they submit their registration
+    Then the registratie process is started carrying a "Buitenlands" diploma
diff --git a/tests/acceptance/Steps/EenDiplomaRouterenSteps.cs b/tests/acceptance/Steps/EenDiplomaRouterenSteps.cs
new file mode 100644
index 0000000..187f3ca
--- /dev/null
+++ b/tests/acceptance/Steps/EenDiplomaRouterenSteps.cs
@@ -0,0 +1,36 @@
+using Acceptance.Support;
+using Big.Application;
+using Big.Domain;
+using Reqnroll;
+using Xunit;
+
+namespace Acceptance.Steps;
+
+/// <summary>Bindings for <c>EenDiplomaRouteren.feature</c> (S-13). Drives the submit use case against
+/// in-memory ports and asserts the registratie process is started carrying the diploma origin — the
+/// domain's contribution to flow 4. The DMN evaluation and the foreign→CBGV-advies routing it drives
+/// are verified live (verify-domain); one instance per scenario.</summary>
+[Binding]
+[Scope(Feature = "Een diploma op herkomst routeren")]
+public sealed class EenDiplomaRouterenSteps
+{
+    private readonly InMemoryRegistrationStore _store = new();
+    private readonly InMemoryWorkflowClient _workflow = new();
+    private DiplomaOrigin _origin;
+
+    [Given("a zorgprofessional with a \"(.*)\" diploma")]
+    public void GivenAZorgprofessionalWithADiploma(string origin)
+        => _origin = Enum.Parse<DiplomaOrigin>(origin, ignoreCase: true);
+
+    [When("they submit their registration")]
+    public async Task WhenTheySubmitTheirRegistration()
+        => await new SubmitRegistration(_store, _workflow).HandleAsync(
+            new SubmitRegistrationCommand("123456782", _origin));
+
+    [Then("the registratie process is started carrying a \"(.*)\" diploma")]
+    public void ThenTheProcessIsStartedCarryingTheDiploma(string expected)
+    {
+        Assert.NotNull(_workflow.StartedFor);
+        Assert.Equal(Enum.Parse<DiplomaOrigin>(expected, ignoreCase: true), _workflow.StartedWithOrigin);
+    }
+}