diff --git a/components/settings/panel/Delete.vue b/components/settings/panel/Delete.vue
index 679a246d..e8edb929 100644
--- a/components/settings/panel/Delete.vue
+++ b/components/settings/panel/Delete.vue
@@ -96,7 +96,15 @@ async function submitDelete() {
   isDeleting.value = true;
 
   try {
-    await workspacesClient.deleteWorkspace(workspace.id);
+    const { osmRequestSucceeded: osmCleanupSucceeded } = await workspacesClient.deleteWorkspace(workspace.id);
+
+    if (!osmCleanupSucceeded) {
+      toast.info(
+        'The workspace has been deleted, but the data may persist for some more time.',
+        { clearOnUrlChange: false }
+      );
+    }
+
     await navigateTo('/dashboard');
   }
   catch (error) {
diff --git a/services/workspaces.ts b/services/workspaces.ts
index c2032c2f..e6d03d0f 100644
--- a/services/workspaces.ts
+++ b/services/workspaces.ts
@@ -79,6 +79,10 @@ export class WorkspacesClientError extends Error {
   }
 }
 
+export interface DeleteWorkspaceResult {
+  osmRequestSucceeded: boolean;
+}
+
 export class WorkspacesClient extends BaseHttpClient implements ICancelableClient {
   #tdeiClient: TdeiClient;
   #osmClient: OsmApiClient;
@@ -241,11 +245,15 @@ export class WorkspacesClient extends BaseHttpClient implements ICancelableClien
     );
   }
 
-  async deleteWorkspace(id: WorkspaceId): Promise<void> {
-    await Promise.all([
+  async deleteWorkspace(id: WorkspaceId): Promise<DeleteWorkspaceResult> {
+    const [workspaceDelete, osmDelete] = await Promise.allSettled([
       this._delete(`workspaces/${id}`),
       this.#osmClient.deleteWorkspace(id),
     ]);
+    if (workspaceDelete.status === 'rejected') {
+      throw workspaceDelete.reason;
+    }
+    return { osmRequestSucceeded: osmDelete.status === 'fulfilled' };
   }
 
   async getLongFormQuestSettings(id: WorkspaceId): Promise<QuestSettings> {
diff --git a/test/e2e/settings.spec.ts b/test/e2e/settings.spec.ts
index 46abcd4f..d283fdf1 100644
--- a/test/e2e/settings.spec.ts
+++ b/test/e2e/settings.spec.ts
@@ -104,6 +104,9 @@ function successToast(page: Page) {
 function errorToast(page: Page) {
   return page.locator('.Toastify__toast--error');
 }
+function infoToast(page: Page) {
+  return page.locator('.Toastify__toast--info');
+}
 
 test.describe('workspace settings', () => {
   // @test e2e: the workspace can be renamed with the "Workspace Title" field, then clicking "Rename";
@@ -433,6 +436,34 @@ test.describe('workspace settings', () => {
     await expect(page).toHaveURL(/\/dashboard$/);
   });
 
+  test('shows an info toast when deletion succeeds but OSM cleanup fails', async ({ page }) => {
+    await seedAuthenticatedSession(page);
+    await stubSettings(page);
+
+    await page.route('**/workspaces/1', async (route) => {
+      if (route.request().method() === 'DELETE') {
+        return route.fulfill({ status: 204, body: '' });
+      }
+      return route.fallback();
+    });
+    await page.route('**/osm/**', (route) => {
+      return route.fulfill({ status: 403, body: 'Forbidden' });
+    });
+
+    await page.goto('/workspace/1/settings');
+
+    const del = page.locator('div.card', { hasText: 'Delete Workspace' });
+    await del.getByRole('button', { name: /^I understand/ }).click();
+    await del.getByRole('textbox').fill('delete');
+    await del.getByRole('button', { name: 'Delete this workspace', exact: true }).click();
+
+    await expect(page).toHaveURL(/\/dashboard$/);
+    await expect(infoToast(page)).toContainText(
+      'The workspace has been deleted, but the data may persist for some more time.'
+    );
+    await expect(errorToast(page)).toHaveCount(0);
+  });
+
   // @test e2e: validate that all the API calls used on this page match the Swagger spec and that
   //            success and error states are handled properly with toasts (snapshot these).
   test('all API calls conform to the OpenAPI spec', async ({ page }) => {
diff --git a/test/unit/services/workspaces.test.ts b/test/unit/services/workspaces.test.ts
index bfeade8a..cff1cccf 100644
--- a/test/unit/services/workspaces.test.ts
+++ b/test/unit/services/workspaces.test.ts
@@ -174,6 +174,49 @@ describe('WorkspacesClient.createBlankWorkspace', () => {
   });
 });
 
+describe('WorkspacesClient.deleteWorkspace', () => {
+  it('reports failed OSM cleanup after the workspace record is deleted', async () => {
+    const deleteOsmWorkspace = vi.fn().mockRejectedValue(new Error('Forbidden'));
+    const client = new WorkspacesClient(
+      TEST_API_BASE,
+      TEST_API_BASE,
+      tdeiClient,
+      { deleteWorkspace: deleteOsmWorkspace } as unknown as OsmApiClient
+    );
+
+    server.use(
+      http.delete(`${TEST_API_BASE}workspaces/1`, () => {
+        return new HttpResponse(null, { status: 204 });
+      })
+    );
+
+    await expect(client.deleteWorkspace(1)).resolves.toEqual({
+      osmRequestSucceeded: false
+    });
+    expect(deleteOsmWorkspace).toHaveBeenCalledWith(1);
+  });
+
+  it('still rejects when the workspace record cannot be deleted', async () => {
+    const deleteOsmWorkspace = vi.fn().mockResolvedValue(undefined);
+    const client = new WorkspacesClient(
+      TEST_API_BASE,
+      TEST_API_BASE,
+      tdeiClient,
+      { deleteWorkspace: deleteOsmWorkspace } as unknown as OsmApiClient
+    );
+
+    server.use(
+      http.delete(`${TEST_API_BASE}workspaces/1`, () => {
+        return new HttpResponse(null, { status: 500, statusText: 'Server Error' });
+      })
+    );
+
+    await expect(client.deleteWorkspace(1)).rejects.toBeInstanceOf(
+      WorkspacesClientError
+    );
+  });
+});
+
 describe('WorkspacesClient.checkWorkspaceTitleAvailability', () => {
   const LEGACY_API_BASE = 'http://legacy-api.test/';
   const NEW_API_BASE = 'http://new-api.test/';