diff --git a/web/src/api/queries.ts b/web/src/api/queries.ts
index d53d672..5741123 100644
--- a/web/src/api/queries.ts
+++ b/web/src/api/queries.ts
@@ -10,6 +10,13 @@ export class HttpError extends Error {
   }
 }
 
+export class FieldRejection extends Error {
+  constructor(public readonly field: string, public readonly code: string) {
+    super(`field rejected: ${field}`);
+    this.name = "FieldRejection";
+  }
+}
+
 type UserView = components["schemas"]["UserView"];
 type LoginRequest = components["schemas"]["LoginRequest"];
 
@@ -179,12 +186,19 @@ export function useSetFields() {
 
   return useMutation({
     mutationFn: async ({ id, fields }: { id: string; fields: Record<string, unknown> }) => {
-      const { response } = await api.PUT("/api/admin/objects/{id}/fields", {
+      const { response, error } = await api.PUT("/api/admin/objects/{id}/fields", {
         params: { path: { id } },
         body: fields as Record<string, never>,
       });
 
-      if (response.status !== 204) throw new Error("set fields failed");
+      if (response.status === 204) return;
+
+      if (response.status === 422 && error && typeof error === "object" && "field" in error) {
+        const detail = error as { field: string; code: string };
+        throw new FieldRejection(detail.field, detail.code);
+      }
+
+      throw new Error("set fields failed");
     },
     onSuccess: (_d, { id }) => {
       void qc.invalidateQueries({ queryKey: ["object", id] });
diff --git a/web/src/i18n/en.json b/web/src/i18n/en.json
index b07cfce..8f798b5 100644
--- a/web/src/i18n/en.json
+++ b/web/src/i18n/en.json
@@ -5,7 +5,7 @@
   "objects": { "title": "Objects", "empty": "No objects yet", "loadError": "Could not load objects", "selectPrompt": "Select an object to view its details", "notFound": "Object not found", "prev": "Previous", "next": "Next", "of": "of", "new": "New object" },
   "fieldsLabels": { "objectNumber": "Object number", "objectName": "Name", "count": "Number of objects", "briefDescription": "Brief description", "currentLocation": "Current location", "currentOwner": "Current owner", "recorder": "Recorder", "recordingDate": "Recording date", "visibility": "Visibility", "flexible": "Catalogue fields" },
   "visibility": { "draft": "Draft", "internal": "Internal", "public": "Public" },
-  "form": { "selectPlaceholder": "— select —", "create": "Create object", "save": "Save", "cancel": "Cancel", "visibility": "Visibility", "draft": "Draft", "internal": "Internal", "required": "This field is required", "rejected": "The server rejected the changes — check required and referenced fields", "flexibleHeading": "Catalogue fields" },
+  "form": { "selectPlaceholder": "— select —", "create": "Create object", "save": "Save", "cancel": "Cancel", "visibility": "Visibility", "draft": "Draft", "internal": "Internal", "required": "This field is required", "rejected": "The server rejected the changes — check required and referenced fields", "fieldRejected": "The field \"{{field}}\" was rejected — check its value", "flexibleHeading": "Catalogue fields" },
   "actions": { "edit": "Edit", "delete": "Delete", "confirmDelete": "Delete this object? This cannot be undone." },
   "labels": { "label": "Label", "externalUri": "External URI (optional)" },
   "vocab": {
diff --git a/web/src/i18n/sv.json b/web/src/i18n/sv.json
index b6c7567..725ab38 100644
--- a/web/src/i18n/sv.json
+++ b/web/src/i18n/sv.json
@@ -5,7 +5,7 @@
   "objects": { "title": "Föremål", "empty": "Inga föremål ännu", "loadError": "Kunde inte ladda föremål", "selectPrompt": "Välj ett föremål för att se detaljer", "notFound": "Föremålet hittades inte", "prev": "Föregående", "next": "Nästa", "of": "av", "new": "Nytt föremål" },
   "fieldsLabels": { "objectNumber": "Föremålsnummer", "objectName": "Namn", "count": "Antal föremål", "briefDescription": "Kort beskrivning", "currentLocation": "Nuvarande plats", "currentOwner": "Nuvarande ägare", "recorder": "Registrerad av", "recordingDate": "Registreringsdatum", "visibility": "Synlighet", "flexible": "Katalogfält" },
   "visibility": { "draft": "Utkast", "internal": "Intern", "public": "Publik" },
-  "form": { "selectPlaceholder": "— välj —", "create": "Skapa föremål", "save": "Spara", "cancel": "Avbryt", "visibility": "Synlighet", "draft": "Utkast", "internal": "Intern", "required": "Fältet är obligatoriskt", "rejected": "Servern avvisade ändringarna — kontrollera obligatoriska och refererade fält", "flexibleHeading": "Katalogfält" },
+  "form": { "selectPlaceholder": "— välj —", "create": "Skapa föremål", "save": "Spara", "cancel": "Avbryt", "visibility": "Synlighet", "draft": "Utkast", "internal": "Intern", "required": "Fältet är obligatoriskt", "rejected": "Servern avvisade ändringarna — kontrollera obligatoriska och refererade fält", "fieldRejected": "Fältet \"{{field}}\" avvisades — kontrollera värdet", "flexibleHeading": "Katalogfält" },
   "actions": { "edit": "Redigera", "delete": "Ta bort", "confirmDelete": "Ta bort detta föremål? Detta kan inte ångras." },
   "labels": { "label": "Etikett", "externalUri": "Extern URI (valfritt)" },
   "vocab": {
diff --git a/web/src/objects/object-edit-form.test.tsx b/web/src/objects/object-edit-form.test.tsx
index 590597d..f5cee74 100644
--- a/web/src/objects/object-edit-form.test.tsx
+++ b/web/src/objects/object-edit-form.test.tsx
@@ -17,6 +17,26 @@ function tree() {
   );
 }
 
+test("edit: fields PUT 422 with field body -> field error message shown and field marked invalid", async () => {
+  server.use(
+    http.get("/api/admin/objects/:id", () =>
+      HttpResponse.json({ ...amphora, fields: { inscription: "old" } }),
+    ),
+    http.put("/api/admin/objects/:id", () => new HttpResponse(null, { status: 204 })),
+    http.put("/api/admin/objects/:id/fields", () =>
+      HttpResponse.json({ field: "inscription", code: "type_mismatch" }, { status: 422 }),
+    ),
+  );
+
+  renderApp(tree(), { route: `/objects/${amphora.id}/edit` });
+
+  await screen.findByDisplayValue("Amphora");
+  await userEvent.click(screen.getByRole("button", { name: /save/i }));
+
+  const alerts = await screen.findAllByText(/inscription.*rejected/i);
+  expect(alerts.length).toBeGreaterThanOrEqual(2);
+});
+
 test("edit: prefilled, save -> PUT core + PUT fields -> back to detail", async () => {
   let putCore: unknown;
   let putFields: unknown;
diff --git a/web/src/objects/object-edit-form.tsx b/web/src/objects/object-edit-form.tsx
index 63bb105..901eebe 100644
--- a/web/src/objects/object-edit-form.tsx
+++ b/web/src/objects/object-edit-form.tsx
@@ -2,7 +2,7 @@ import { useState } from "react";
 import { useLocation, useNavigate, useParams } from "react-router-dom";
 import { useTranslation } from "react-i18next";
 
-import { useObject, useUpdateObject, useSetFields } from "../api/queries";
+import { useObject, useUpdateObject, useSetFields, FieldRejection } from "../api/queries";
 import { ObjectForm, type ObjectCore, type ObjectFormValues } from "./object-form";
 
 export function ObjectEditForm() {
@@ -15,8 +15,14 @@ export function ObjectEditForm() {
   const update = useUpdateObject();
   const setFields = useSetFields();
 
+  const locationState = location.state as { fieldsError?: boolean; fieldErrorKey?: string } | null;
+
   const [error, setError] = useState<string | null>(
-    (location.state as { fieldsError?: boolean } | null)?.fieldsError ? t("form.rejected") : null,
+    locationState?.fieldsError ? t("form.rejected") : null,
+  );
+
+  const [fieldErrorKey, setFieldErrorKey] = useState<string | null>(
+    locationState?.fieldErrorKey ?? null,
   );
 
   if (isLoading) return <div className="p-4" role="status" aria-label="loading" />;
@@ -38,12 +44,19 @@ export function ObjectEditForm() {
 
   const onSubmit = async (values: ObjectFormValues) => {
     setError(null);
+    setFieldErrorKey(null);
 
     try {
       await update.mutateAsync({ id: id!, body: values.core });
       await setFields.mutateAsync({ id: id!, fields: values.fields });
-    } catch {
-      setError(t("form.rejected"));
+    } catch (e) {
+      if (e instanceof FieldRejection) {
+        setFieldErrorKey(e.field);
+        setError(t("form.fieldRejected", { field: e.field }));
+      } else {
+        setError(t("form.rejected"));
+      }
+
       return;
     }
 
@@ -55,6 +68,7 @@ export function ObjectEditForm() {
       mode="edit"
       defaults={defaults}
       formError={error}
+      fieldErrorKey={fieldErrorKey}
       onSubmit={onSubmit}
       onCancel={() => navigate(`/objects/${id}`)}
     />
diff --git a/web/src/objects/object-form.tsx b/web/src/objects/object-form.tsx
index b450502..de84807 100644
--- a/web/src/objects/object-form.tsx
+++ b/web/src/objects/object-form.tsx
@@ -1,3 +1,4 @@
+import { useEffect } from "react";
 import { useForm } from "react-hook-form";
 import { useTranslation } from "react-i18next";
 
@@ -47,12 +48,14 @@ export function ObjectForm({
   onSubmit,
   onCancel,
   formError,
+  fieldErrorKey,
 }: {
   mode: "create" | "edit";
   defaults?: { core: ObjectCore; fields: Record<string, unknown> };
   onSubmit: (values: ObjectFormValues) => void;
   onCancel: () => void;
   formError?: string | null;
+  fieldErrorKey?: string | null;
 }) {
   const { t } = useTranslation();
 
@@ -68,6 +71,15 @@ export function ObjectForm({
 
   const { register, handleSubmit, formState: { errors } } = form;
 
+  useEffect(() => {
+    if (fieldErrorKey) {
+      form.setError(`fields.${fieldErrorKey}` as never, {
+        type: "server",
+        message: t("form.fieldRejected", { field: fieldErrorKey }),
+      });
+    }
+  }, [fieldErrorKey, form, t]);
+
   const submit = handleSubmit((data) => {
     const fields = pruneFields(data.fields);
 
@@ -149,7 +161,7 @@ export function ObjectForm({
 
               {errors.fields?.[def.key] && (
                 <p role="alert" className="text-xs text-red-600">
-                  {t("form.required")}
+                  {errors.fields[def.key]?.message ?? t("form.required")}
                 </p>
               )}
             </div>
diff --git a/web/src/objects/object-new-page.tsx b/web/src/objects/object-new-page.tsx
index d6010bc..6f69c3a 100644
--- a/web/src/objects/object-new-page.tsx
+++ b/web/src/objects/object-new-page.tsx
@@ -3,7 +3,7 @@ import { useNavigate } from "react-router-dom";
 import { useTranslation } from "react-i18next";
 
 import { ObjectForm, type ObjectFormValues } from "./object-form";
-import { useCreateObject, useSetFields } from "../api/queries";
+import { useCreateObject, useSetFields, FieldRejection } from "../api/queries";
 
 export function ObjectNewPage() {
   const { t } = useTranslation();
@@ -32,8 +32,9 @@ export function ObjectNewPage() {
     if (Object.keys(values.fields).length > 0) {
       try {
         await setFields.mutateAsync({ id, fields: values.fields });
-      } catch {
-        navigate(`/objects/${id}/edit`, { state: { fieldsError: true } });
+      } catch (e) {
+        const fieldErrorKey = e instanceof FieldRejection ? e.field : undefined;
+        navigate(`/objects/${id}/edit`, { state: { fieldsError: true, fieldErrorKey } });
         return;
       }
     }