diff --git a/app/features/tasks/router.py b/app/features/tasks/router.py
index 97fbd0f8..9cd23f19 100644
--- a/app/features/tasks/router.py
+++ b/app/features/tasks/router.py
@@ -151,6 +151,22 @@ def _serialize(model: Any) -> dict:
     return _model(model).model_dump()
 
 
+async def _require_timer_or_handler(task: Task, handler: TaskHandle) -> None:
+    if task.timer:
+        return
+
+    if task.handler_enabled is False:
+        msg = "Task requires a timer when the handler is disabled."
+        raise ValueError(msg)
+
+    result = await handler.inspect(url=task.url, preset=task.preset, static_only=True)
+    if isinstance(result, TaskResult) and result.metadata.get("matched") is True:
+        return
+
+    msg = "Task requires a timer when no supported handler matches the URL."
+    raise ValueError(msg)
+
+
 @route("GET", "api/tasks/", "tasks_list")
 async def tasks_list(request: Request, repo: TasksRepository, encoder: Encoder) -> Response:
     page, per_page = normalize_pagination(request)
@@ -166,7 +182,13 @@ async def tasks_list(request: Request, repo: TasksRepository, encoder: Encoder)
 
 
 @route("POST", "api/tasks/", "tasks_add")
-async def tasks_add(request: Request, repo: TasksRepository, encoder: Encoder, notify: EventBus) -> Response:
+async def tasks_add(
+    request: Request,
+    repo: TasksRepository,
+    encoder: Encoder,
+    notify: EventBus,
+    handler: TaskHandle,
+) -> Response:
     data = await request.json()
 
     if isinstance(data, dict):
@@ -205,6 +227,7 @@ async def tasks_add(request: Request, repo: TasksRepository, encoder: Encoder, n
             status=web.HTTPConflict.status_code,
         )
 
+    pending_tasks: list[dict[str, Any]] = []
     created_tasks: list[dict[str, Any]] = []
     base_settings = first_task.model_dump(exclude={"id", "name", "url", "created_at", "updated_at"})
 
@@ -243,11 +266,23 @@ async def tasks_add(request: Request, repo: TasksRepository, encoder: Encoder, n
 
         try:
             validated = Task.model_validate(task_dict)
-            task_data = validated.model_dump()
         except ValidationError as exc:
-            LOG.warning(f"Skipping task {idx}: validation failed - {exc}")
-            continue
+            return web.json_response(
+                data={"error": "Failed to validate task.", "detail": format_validation_errors(exc)},
+                status=web.HTTPBadRequest.status_code,
+            )
 
+        try:
+            await _require_timer_or_handler(validated, handler)
+        except ValueError as exc:
+            return web.json_response(
+                data={"error": str(exc)},
+                status=web.HTTPBadRequest.status_code,
+            )
+
+        pending_tasks.append(validated.model_dump())
+
+    for idx, task_data in enumerate(pending_tasks):
         try:
             created = await repo.create(task_data)
             saved = _serialize(created)
@@ -304,7 +339,13 @@ async def tasks_delete(request: Request, repo: TasksRepository, encoder: Encoder
 
 
 @route("PATCH", r"api/tasks/{id:\d+}", "tasks_patch")
-async def tasks_patch(request: Request, repo: TasksRepository, encoder: Encoder, notify: EventBus) -> Response:
+async def tasks_patch(
+    request: Request,
+    repo: TasksRepository,
+    encoder: Encoder,
+    notify: EventBus,
+    handler: TaskHandle,
+) -> Response:
     if not (identifier := request.match_info.get("id")):
         return web.json_response({"error": "ID required"}, status=web.HTTPBadRequest.status_code)
 
@@ -334,6 +375,16 @@ async def tasks_patch(request: Request, repo: TasksRepository, encoder: Encoder,
             status=web.HTTPConflict.status_code,
         )
 
+    merged = _model(model).model_copy(update=validated.model_dump(exclude_unset=True))
+
+    try:
+        await _require_timer_or_handler(merged, handler)
+    except ValueError as exc:
+        return web.json_response(
+            data={"error": str(exc)},
+            status=web.HTTPBadRequest.status_code,
+        )
+
     updated = _serialize(await repo.update(model.id, validated.model_dump(exclude_unset=True)))
     notify.emit(Events.CONFIG_UPDATE, data=ConfigEvent(feature=CEFeature.TASKS, action=CEAction.UPDATE, data=updated))
     return web.json_response(
@@ -344,7 +395,13 @@ async def tasks_patch(request: Request, repo: TasksRepository, encoder: Encoder,
 
 
 @route("PUT", r"api/tasks/{id:\d+}", "tasks_update")
-async def tasks_update(request: Request, repo: TasksRepository, encoder: Encoder, notify: EventBus) -> Response:
+async def tasks_update(
+    request: Request,
+    repo: TasksRepository,
+    encoder: Encoder,
+    notify: EventBus,
+    handler: TaskHandle,
+) -> Response:
     if not (identifier := request.match_info.get("id")):
         return web.json_response({"error": "ID required"}, status=web.HTTPBadRequest.status_code)
 
@@ -374,6 +431,14 @@ async def tasks_update(request: Request, repo: TasksRepository, encoder: Encoder
             status=web.HTTPConflict.status_code,
         )
 
+    try:
+        await _require_timer_or_handler(validated, handler)
+    except ValueError as exc:
+        return web.json_response(
+            data={"error": str(exc)},
+            status=web.HTTPBadRequest.status_code,
+        )
+
     updated = _serialize(await repo.update(model.id, validated.model_dump(exclude_unset=True)))
     notify.emit(Events.CONFIG_UPDATE, data=ConfigEvent(feature=CEFeature.TASKS, action=CEAction.UPDATE, data=updated))
 
diff --git a/app/features/tasks/tests/test_tasks_router.py b/app/features/tasks/tests/test_tasks_router.py
new file mode 100644
index 00000000..d3064427
--- /dev/null
+++ b/app/features/tasks/tests/test_tasks_router.py
@@ -0,0 +1,183 @@
+from __future__ import annotations
+
+from types import SimpleNamespace
+
+import pytest
+import pytest_asyncio
+from aiohttp import web
+from aiohttp.test_utils import make_mocked_request
+
+from app.features.tasks import router
+from app.features.tasks.definitions.results import TaskFailure, TaskResult
+from app.features.tasks.repository import TasksRepository
+from app.library.encoder import Encoder
+from app.library.sqlite_store import SqliteStore
+from app.tests.helpers import make_in_memory_db_path
+
+
+@pytest_asyncio.fixture
+async def repo():
+    TasksRepository._reset_singleton()
+    SqliteStore._reset_singleton()
+
+    store = SqliteStore(db_path=make_in_memory_db_path("tasks-router"))
+    await store.get_connection()
+
+    repository = TasksRepository.get_instance()
+
+    yield repository
+
+    await store.close()
+    TasksRepository._reset_singleton()
+    SqliteStore._reset_singleton()
+
+
+@pytest.fixture(autouse=True)
+def patch_get_info(monkeypatch: pytest.MonkeyPatch) -> None:
+    async def _fake_get_info(_url: str, _preset: str) -> tuple[None, None]:
+        return (None, None)
+
+    monkeypatch.setattr(router, "_get_info", _fake_get_info)
+
+
+def _json_request(method: str, path: str, payload: object, *, match_info: dict[str, str] | None = None) -> web.Request:
+    request = make_mocked_request(method, path, match_info=match_info or {}, app=SimpleNamespace())
+
+    async def _json() -> object:
+        return payload
+
+    request.json = _json  # type: ignore[attr-defined]
+    return request
+
+
+class _Notify:
+    def emit(self, *_args, **_kwargs) -> None:
+        return None
+
+
+class _Handler:
+    def __init__(self, matched: bool | dict[str, bool]) -> None:
+        self._matched = matched
+
+    async def inspect(self, *, url: str, preset: str | None = None, static_only: bool = False, **_kwargs):
+        del preset, static_only
+
+        if isinstance(self._matched, dict):
+            matched = self._matched.get(url, False)
+        else:
+            matched = self._matched
+
+        if matched:
+            return TaskResult(metadata={"matched": True, "handler": "TestHandler"})
+
+        return TaskFailure(message="No handler", metadata={"matched": False, "handler": None})
+
+
+@pytest.mark.asyncio
+async def test_add_requires_timer_without_handler(repo) -> None:
+    request = _json_request(
+        "POST",
+        "/api/tasks/",
+        {"name": "No Timer", "url": "https://example.com/channel"},
+    )
+
+    response = await router.tasks_add(request, repo, Encoder(), _Notify(), _Handler(matched=False))
+
+    assert response.status == web.HTTPBadRequest.status_code
+    assert b"requires a timer" in response.body
+    assert await repo.list() == []
+
+
+@pytest.mark.asyncio
+async def test_add_all_or_nothing(repo) -> None:
+    request = _json_request(
+        "POST",
+        "/api/tasks/",
+        [
+            {"name": "First", "url": "https://example.com/first"},
+            {"url": "https://example.com/second"},
+        ],
+    )
+
+    response = await router.tasks_add(
+        request,
+        repo,
+        Encoder(),
+        _Notify(),
+        _Handler({"https://example.com/first": True, "https://example.com/second": False}),
+    )
+
+    assert response.status == web.HTTPBadRequest.status_code
+    assert b"requires a timer" in response.body
+    assert await repo.list() == []
+
+
+@pytest.mark.asyncio
+async def test_add_allows_handler_only(repo) -> None:
+    request = _json_request(
+        "POST",
+        "/api/tasks/",
+        {"name": "Handler Only", "url": "https://example.com/feed"},
+    )
+
+    response = await router.tasks_add(request, repo, Encoder(), _Notify(), _Handler(matched=True))
+
+    assert response.status == web.HTTPOk.status_code
+    items = await repo.list()
+    assert len(items) == 1
+    assert items[0].name == "Handler Only"
+
+
+@pytest.mark.asyncio
+async def test_update_requires_timer_without_handler(repo) -> None:
+    item = await repo.create({"name": "Needs Timer", "url": "https://example.com/a", "timer": "0 0 * * *"})
+
+    request = _json_request(
+        "PUT",
+        f"/api/tasks/{item.id}",
+        {"name": item.name, "url": item.url, "timer": "", "preset": "", "folder": "", "template": "", "cli": ""},
+        match_info={"id": str(item.id)},
+    )
+
+    response = await router.tasks_update(request, repo, Encoder(), _Notify(), _Handler(matched=False))
+
+    assert response.status == web.HTTPBadRequest.status_code
+    refreshed = await repo.get(item.id)
+    assert refreshed is not None
+    assert refreshed.timer == "0 0 * * *"
+
+
+@pytest.mark.asyncio
+async def test_patch_requires_timer_without_handler(repo) -> None:
+    item = await repo.create({"name": "Patch Timer", "url": "https://example.com/b", "timer": "0 0 * * *"})
+
+    request = _json_request(
+        "PATCH",
+        f"/api/tasks/{item.id}",
+        {"timer": ""},
+        match_info={"id": str(item.id)},
+    )
+
+    response = await router.tasks_patch(request, repo, Encoder(), _Notify(), _Handler(matched=False))
+
+    assert response.status == web.HTTPBadRequest.status_code
+    refreshed = await repo.get(item.id)
+    assert refreshed is not None
+    assert refreshed.timer == "0 0 * * *"
+
+
+@pytest.mark.asyncio
+async def test_patch_requires_timer_when_handler_disabled(repo) -> None:
+    item = await repo.create({"name": "Disabled Handler", "url": "https://example.com/c", "timer": "0 0 * * *"})
+
+    request = _json_request(
+        "PATCH",
+        f"/api/tasks/{item.id}",
+        {"timer": "", "handler_enabled": False},
+        match_info={"id": str(item.id)},
+    )
+
+    response = await router.tasks_patch(request, repo, Encoder(), _Notify(), _Handler(matched=True))
+
+    assert response.status == web.HTTPBadRequest.status_code
+    assert b"handler is disabled" in response.body
diff --git a/ui/app/components/TaskForm.vue b/ui/app/components/TaskForm.vue
index f753cea4..5f0c9c4f 100644
--- a/ui/app/components/TaskForm.vue
+++ b/ui/app/components/TaskForm.vue
@@ -367,7 +367,9 @@
                   <UIcon name="i-lucide-rss" class="size-4 text-toned" />
                   <p class="text-sm font-semibold text-default">Enable Handler</p>
                 </div>
-                <p class="text-xs text-toned">Handlers run regardless of task timer.</p>
+                <p class="text-xs text-toned">
+                  Tasks without a supported handler must use a timer.
+                </p>
               </div>
               <USwitch v-model="form.handler_enabled" :disabled="addInProgress" />
             </div>
@@ -443,6 +445,10 @@
             scheduled downloads to yt-dlp. Disable <code>Enable Handler</code> to disable RSS
             monitoring.
           </li>
+          <li>
+            <strong>Timer Requirement:</strong> if no supported handler matches the URL, you must
+            set a CRON timer before saving.
+          </li>
         </ul>
       </template>
     </UAlert>
@@ -523,6 +529,7 @@ const emitter = defineEmits<{
 const toast = useNotification();
 const config = useYtpConfig();
 const dialog = useDialog();
+const tasksComposable = useTasks();
 const { findPreset, getPresetDefault, selectItems } = usePresetOptions();
 const showImport = useStorage('showTaskImport', false);
 
@@ -786,6 +793,13 @@ const checkInfo = async (): Promise<void> => {
     form.cli = form.cli.trim();
   }
 
+  try {
+    await requireTimerForTask(form);
+  } catch (error: any) {
+    toast.error(error.message);
+    return;
+  }
+
   if (urls.length === 1) {
     emitter('submit', {
       reference: toRaw(props.reference),
@@ -811,12 +825,32 @@ const checkInfo = async (): Promise<void> => {
       } as Task;
     }
 
-    return { url } as Task;
+    return {
+      url,
+      preset: form.preset,
+      timer: form.timer,
+      handler_enabled: form.handler_enabled,
+    } as Task;
+  });
+
+  try {
+    await Promise.all(tasks.map((item) => requireTimerForTask(item)));
+  } catch (error: any) {
+    toast.error(error.message);
+    return;
+  }
+
+  const submitTasks: Task[] = tasks.map((item, idx) => {
+    if (idx === 0) {
+      return item;
+    }
+
+    return { url: item.url } as Task;
   });
 
   emitter('submit', {
     reference: toRaw(props.reference),
-    task: tasks,
+    task: submitTasks,
     archive_all: archiveAllAfterAdd.value,
   });
 };
@@ -943,6 +977,34 @@ const convertCurrentUrl = async (): Promise<void> => {
   form.url = await convert_url(form.url);
 };
 
+const requireTimerForTask = async (
+  item: Pick<Task, 'url' | 'preset' | 'timer' | 'handler_enabled'>,
+): Promise<void> => {
+  if (item.timer?.trim()) {
+    return;
+  }
+
+  if (item.handler_enabled === false) {
+    throw new Error('This task needs a CRON timer because the handler is disabled.');
+  }
+
+  const result = await tasksComposable.inspectTaskHandler({
+    url: item.url,
+    preset: item.preset,
+    static_only: true,
+  });
+
+  if (!result) {
+    throw new Error('Failed to verify handler support. Set a CRON timer or try again.');
+  }
+
+  if (result?.matched) {
+    return;
+  }
+
+  throw new Error('This task needs a CRON timer because no supported handler matches the URL.');
+};
+
 const getDefault = (type: 'cookies' | 'cli' | 'template' | 'folder', ret: string = '') => {
   if (false !== hasFormatInConfig.value || !form.preset) {
     return ret;
diff --git a/ui/app/pages/tasks.vue b/ui/app/pages/tasks.vue
index 713a76e4..432da30a 100644
--- a/ui/app/pages/tasks.vue
+++ b/ui/app/pages/tasks.vue
@@ -661,8 +661,8 @@
             <code>Actions &gt; Archive All</code> to mark existing items as already downloaded.
           </li>
           <li>
-            <strong>Custom Handlers:</strong> Leave timer empty for custom handler definitions. The
-            handler runs hourly and doesn't require timer.
+            <strong>Timer Requirement:</strong> Tasks must have either a valid timer or a supported
+            handler. If the URL does not match a handler, set a CRON timer.
           </li>
           <li>
             <strong>Generate metadata:</strong> will attempt first to save metadata based on the
diff --git a/ui/tests/composables/useTasks.test.ts b/ui/tests/composables/useTasks.test.ts
index 8940cbb4..d515095c 100644
--- a/ui/tests/composables/useTasks.test.ts
+++ b/ui/tests/composables/useTasks.test.ts
@@ -258,6 +258,29 @@ describe('useTasks', () => {
       requestSpy.mockRestore()
     })
 
+    it('store_timer_required_error', async () => {
+      const requestSpy = spyOn(utils, 'request')
+      requestSpy.mockResolvedValueOnce(
+        createMockResponse({
+          ok: false,
+          status: 400,
+          jsonData: { error: 'Task requires a timer when no supported handler matches the URL.' },
+        }),
+      )
+
+      const tasks = useTasks()
+      const newTask = { ...mockTask }
+      delete (newTask as any).id
+
+      const result = await tasks.createTask(newTask)
+
+      expect(result).toBeNull()
+      expect(tasks.lastError.value).toBe(
+        'Task requires a timer when no supported handler matches the URL.',
+      )
+      requestSpy.mockRestore()
+    })
+
   })
 
   describe('updateTask', () => {
@@ -280,6 +303,26 @@ describe('useTasks', () => {
       requestSpy.mockRestore()
     })
 
+    it('store_update_timer_error', async () => {
+      const requestSpy = spyOn(utils, 'request')
+      requestSpy.mockResolvedValueOnce(
+        createMockResponse({
+          ok: false,
+          status: 400,
+          jsonData: { error: 'Task requires a timer when the handler is disabled.' },
+        }),
+      )
+
+      const tasks = useTasks()
+      const updated = { ...mockTask, timer: '', handler_enabled: false }
+
+      const result = await tasks.updateTask(1, updated)
+
+      expect(result).toBeNull()
+      expect(tasks.lastError.value).toBe('Task requires a timer when the handler is disabled.')
+      requestSpy.mockRestore()
+    })
+
     it('strip_update_id', async () => {
       const requestSpy = spyOn(utils, 'request')
       requestSpy.mockResolvedValueOnce(
@@ -318,6 +361,26 @@ describe('useTasks', () => {
       requestSpy.mockRestore()
     })
 
+    it('store_patch_timer_error', async () => {
+      const requestSpy = spyOn(utils, 'request')
+      requestSpy.mockResolvedValueOnce(
+        createMockResponse({
+          ok: false,
+          status: 400,
+          jsonData: { error: 'Task requires a timer when no supported handler matches the URL.' },
+        }),
+      )
+
+      const tasks = useTasks()
+      const result = await tasks.patchTask(1, { timer: '' })
+
+      expect(result).toBeNull()
+      expect(tasks.lastError.value).toBe(
+        'Task requires a timer when no supported handler matches the URL.',
+      )
+      requestSpy.mockRestore()
+    })
+
   })
 
   describe('deleteTask', () => {