Why phone reminders don't fire: a checklist for Android and iPhone

You set a reminder, and nothing happened. Or it arrived two hours late. Almost every time, the reminder app is not the problem. The phone is quietly stopping it. Phones are built to save battery and reduce interruptions, and those good intentions get in the way of reminders.

Work through this checklist from the top. Most people fix the problem in the first three steps. Menu names vary slightly between phone brands, so use the search box in your Settings app if you cannot find an item.

1. Check that notifications are allowed

• Android: Settings → Apps → your reminder app → Notifications. Make sure notifications are on, and that the reminder category is not set to silent.
• iPhone: Settings → Notifications → your reminder app. Turn on Allow Notifications, and enable Lock Screen, Notification Centre and Banners.

If you tapped “Don’t allow” the first time the app asked, this is where you undo it.

2. Check Do Not Disturb and Focus modes

• iPhone: Open Settings → Focus. Sleep, Work or Do Not Disturb can silence your reminder app. Either allow the app in that Focus, or make the Focus end before the reminder.
• Android: Settings → Sound → Do Not Disturb. Add your reminder app to the exceptions, and check any scheduled “bedtime” mode.

3. Turn off battery restrictions for the app (Android)

This is the most common cause on Android.

• Settings → Apps → your reminder app → Battery. Choose Unrestricted (or “Don’t optimise”).
• Some brands add their own layer: Xiaomi, Oppo, Vivo, OnePlus and Samsung have “auto-start”, “background activity” or “sleeping apps” lists. Make sure your reminder app is allowed to start and run in the background, and is not in the “sleeping” list.

4. Allow exact alarms (Android 12 and later)

Recent Android versions restrict apps from setting exact-time alarms unless you allow it. Look under Settings → Apps → Special app access → Alarms & reminders and allow your reminder app.

5. Check Low Power Mode and Battery Saver

Low Power Mode on iPhone and Battery Saver on Android reduce background activity. A well-built reminder app schedules its alerts on the phone itself, so they should still fire. Smart Reminder is built to deliver reminders in battery saver and Low Power Mode. But if you still miss alerts, turn the saver off for a day to see whether it makes a difference.

6. Make sure Background App Refresh is on (iPhone)

Settings → General → Background App Refresh. Keep it on for your reminder app, particularly if it syncs tasks across devices.

7. Check the volume and the ringer

It sounds obvious, but a muted ringer, a low notification volume or a silent switch is behind many “missed” reminders. Test one reminder two minutes ahead with the phone locked.

8. Check the date, time and time zone

If your phone’s clock is set manually, or the time zone is wrong after travel, reminders fire at the wrong time. Turn on automatic date and time.

9. Update the app and the phone

Old versions of an app or of the operating system can have notification bugs. Update both.

10. Do a two-minute test

1. Create a reminder for two minutes from now.
2. Lock the phone and put it down.
3. See whether it arrives. If it does, try again in a different situation, for example with Focus mode on.

Now you know which setting is the culprit.

When one alert is not enough

Even with perfect settings, a phone can be switched off, offline or simply in a pocket while you are busy. For tasks that matter, build in a second channel. In Smart Reminder, you can switch on an email reminder for a task, and if it is still pending or snoozed after its due time, you get a backup email within minutes. Our guide to reminders with an email backup explains how, and how to stop forgetting bills and renewals shows how to use it for the tasks that matter most.

For anything critical, such as medication, add a second safeguard that is not a phone, for example a family member or an alarm clock. See our checklist for choosing a medication reminder app.

Still stuck?

Tell me your phone model and what you tried, and I will help: see the support page.