diff --git a/frontend/src/routes/[fam]/+layout.server.ts b/frontend/src/routes/[fam]/+layout.server.ts
index c1728cf..628ece6 100644
--- a/frontend/src/routes/[fam]/+layout.server.ts
+++ b/frontend/src/routes/[fam]/+layout.server.ts
@@ -1,3 +1,4 @@
+import { redirect } from '@sveltejs/kit';
 import { createPbClient } from '$lib/server/pocketbase';
 import { createServices, type ChatActor } from '$lib/server/services';
 import { ensureFamAccess } from '$lib/server/access';
@@ -63,6 +64,17 @@ export async function load(event) {
 			fam = res.fam;
 			famAccess = res.access;
 		}
+		// Canonical URL: the [fam] segment must be the family SLUG, never the PB
+		// id. If someone lands on /{famId}/... (a stale shortcut, bookmark, or a
+		// login that fell back to the id), rewrite the first path segment to the
+		// slug so the id is replaced everywhere it'd otherwise persist.
+		const paramFam = event.params.fam;
+		const canonicalSlug = fam?.slug;
+		if (canonicalSlug && paramFam && paramFam !== canonicalSlug) {
+			const rest = event.url.pathname.replace(`/${paramFam}`, '') || '/';
+			const qs = event.url.search;
+			throw redirect(303, `/${encodeURIComponent(canonicalSlug)}${rest}${qs}`);
+		}
 	}
 
 	return {
diff --git a/frontend/src/routes/[fam]/+layout.svelte b/frontend/src/routes/[fam]/+layout.svelte
index 47e4f7c..055a96d 100644
--- a/frontend/src/routes/[fam]/+layout.svelte
+++ b/frontend/src/routes/[fam]/+layout.svelte
@@ -117,7 +117,7 @@
 	$effect(() => {
 		if (!page.data.session) return;
 		recordShortcut({
-			famSlug: page.params.fam || '',
+			famSlug: (page.data.fam?.slug as string) || page.params.fam || '',
 			famName: (page.data.fam?.name as string) || page.params.fam || '',
 			userName: page.data.role === 'parent' ? '' : page.params.username || ''
 		});