diff --git a/web/src/authorities/authorities-page.tsx b/web/src/authorities/authorities-page.tsx
index d9b5d05..06d03f2 100644
--- a/web/src/authorities/authorities-page.tsx
+++ b/web/src/authorities/authorities-page.tsx
@@ -1,37 +1,32 @@
 import { useState, type FormEvent } from "react";
-import { NavLink, useParams } from "react-router-dom";
+import { NavLink, Navigate, useParams } from "react-router-dom";
 import { useTranslation } from "react-i18next";
 
 import type { components } from "../api/schema";
 import { useAuthorities, useCreateAuthority } from "../api/queries";
 import { LabelEditor } from "../components/label-editor";
 import { Button } from "@/components/ui/button";
+import { labelText } from "../lib/labels";
 
 type LabelInput = components["schemas"]["LabelInput"];
-type LabelView = components["schemas"]["LabelView"];
 
 const KINDS = ["person", "organisation", "place"] as const;
 
-function labelText(labels: LabelView[], lang: string): string {
-  return (
-    labels.find((l) => l.lang === lang)?.label ??
-    labels.find((l) => l.lang === "en")?.label ??
-    labels[0]?.label ??
-    ""
-  );
-}
-
 export function AuthoritiesPage() {
   const { t, i18n } = useTranslation();
-  const { kind = "person" } = useParams();
+  const { kind } = useParams();
   const lang = i18n.language.startsWith("sv") ? "sv" : "en";
 
-  const { data: authorities } = useAuthorities(kind);
+  const isValidKind = (KINDS as readonly string[]).includes(kind ?? "");
+
+  const { data: authorities } = useAuthorities(isValidKind ? (kind as string) : "person");
   const create = useCreateAuthority();
 
   const [labels, setLabels] = useState<LabelInput[]>([]);
   const [error, setError] = useState(false);
 
+  if (!isValidKind) return <Navigate to="/authorities/person" replace />;
+
   const onCreate = (event: FormEvent) => {
     event.preventDefault();
 
@@ -42,7 +37,7 @@ export function AuthoritiesPage() {
 
     setError(false);
     create.mutate(
-      { kind, external_uri: null, labels },
+      { kind: kind as string, external_uri: null, labels },
       { onSuccess: () => setLabels([]) },
     );
   };
diff --git a/web/src/authorities/authorities.test.tsx b/web/src/authorities/authorities.test.tsx
index d9b45d0..58e49c3 100644
--- a/web/src/authorities/authorities.test.tsx
+++ b/web/src/authorities/authorities.test.tsx
@@ -35,3 +35,23 @@ test("kind tabs link to the other kinds", async () => {
   renderApp(tree(), { route: "/authorities/person" });
   expect(await screen.findByRole("link", { name: /place/i })).toHaveAttribute("href", "/authorities/place");
 });
+
+test("create without EN label shows required alert and does not POST", async () => {
+  let posted = false;
+  server.use(
+    http.post("/api/admin/authorities", () => {
+      posted = true;
+      return HttpResponse.json({ id: "a-x" }, { status: 201 });
+    }),
+  );
+  renderApp(tree(), { route: "/authorities/person" });
+  expect(await screen.findByText("Ada Lovelace")).toBeInTheDocument();
+  await userEvent.click(screen.getByRole("button", { name: /create/i }));
+  expect(screen.getByRole("alert")).toBeInTheDocument();
+  expect(posted).toBe(false);
+});
+
+test("unknown kind redirects to person list", async () => {
+  renderApp(tree(), { route: "/authorities/banana" });
+  expect(await screen.findByText("Ada Lovelace")).toBeInTheDocument();
+});
diff --git a/web/src/lib/labels.ts b/web/src/lib/labels.ts
new file mode 100644
index 0000000..6485cd5
--- /dev/null
+++ b/web/src/lib/labels.ts
@@ -0,0 +1,12 @@
+import type { components } from "../api/schema";
+
+type LabelView = components["schemas"]["LabelView"];
+
+export function labelText(labels: LabelView[], lang: string): string {
+  return (
+    labels.find((l) => l.lang === lang)?.label ??
+    labels.find((l) => l.lang === "en")?.label ??
+    labels[0]?.label ??
+    ""
+  );
+}
diff --git a/web/src/vocab/vocabulary-terms.tsx b/web/src/vocab/vocabulary-terms.tsx
index 7c9d95b..f6cb86f 100644
--- a/web/src/vocab/vocabulary-terms.tsx
+++ b/web/src/vocab/vocabulary-terms.tsx
@@ -8,18 +8,9 @@ import { LabelEditor } from "../components/label-editor";
 import { Button } from "@/components/ui/button";
 import { Input } from "@/components/ui/input";
 import { Label } from "@/components/ui/label";
+import { labelText } from "../lib/labels";
 
 type LabelInput = components["schemas"]["LabelInput"];
-type LabelView = components["schemas"]["LabelView"];
-
-function labelText(labels: LabelView[], lang: string): string {
-  return (
-    labels.find((l) => l.lang === lang)?.label ??
-    labels.find((l) => l.lang === "en")?.label ??
-    labels[0]?.label ??
-    ""
-  );
-}
 
 export function VocabularyTerms() {
   const { t, i18n } = useTranslation();