A customer says they messaged you an hour ago. You open WhatsApp and there it is, with no alert on your phone. Or every message turns up in a batch when you unlock the screen.
That usually doesn't mean the message failed. Sending the message and alerting you about it are two separate steps, and the second depends on your phone's permissions, background data and battery settings. WhatsApp's help also says your device settings override WhatsApp settings, so a switch that looks right inside the app can still be overruled by the phone. Start by working out which step failed. Lock your phone, ask someone to send you a message, wait a minute, then look.
- No alert, but the message is already there when you open WhatsApp: WhatsApp's help calls this a notification issue. Work through causes one to four.
- An alert appears but makes no sound: WhatsApp says the usual causes are a tone set to 'Silent' or 'None', your device's sound settings, or Do Not Disturb or Focus. If you can see the alert, delivery is working, so check sound first.
- Alerts come from individual chats but never from one group: see cause five.
- Your phone is fine and only a tablet or second phone stays quiet: see cause six.
- Messages don't appear even with the app open: this is more likely your connection. WhatsApp says the most common reason for trouble sending and receiving chats is a poor internet connection, and it also links missing notifications to the same thing. Try restarting the phone or switching to another network.
Cause 1: Notifications are off on the phone or in WhatsApp
Check the phone first, because it wins. Then check WhatsApp's own settings. Android menu names can differ by manufacturer and version.
On Android 13 and later, apps also need permission to send notifications at all.
- Android, phone: go to Settings > Apps > WhatsApp > Notifications and turn on 'Allow notifications'.
- Android, WhatsApp: tap 'More' (the three vertical dots) > 'Settings' > 'Notifications', and check the tone isn't set to 'Silent'.
- Android, reset: in the same place, tap 'More' > 'Reset notification settings' > 'Reset'. This only restores WhatsApp's own settings, not the phone's.
- iPhone, phone: go to Settings > Notifications > WhatsApp and turn on 'Allow Notifications', then choose how alerts appear. Apple notes that sounds won't play if the phone is silenced or the volume is all the way down.
- iPhone, WhatsApp: tap 'Settings' > 'Notifications' and turn on 'Show notifications' under both 'Message notifications' and 'Group notifications'.
- iPhone, reset: in the same place, tap 'Reset notification settings' > 'Reset'.
- Update WhatsApp from the Play Store or App Store. WhatsApp lists an outdated version among the causes.
Cause 2: Focus, Do Not Disturb or a Scheduled Summary is holding alerts back
These modes can switch on by schedule without you touching anything, so alerts vanish at night and return in the morning.
On iPhone, Apple's Scheduled Summary is a separate feature from Focus, and easy to forget you set up. It collects notifications from the apps you pick and delivers them at the times you choose, which looks exactly like a delay. If you wear an Apple Watch, also remember that Apple sends alerts to the Watch rather than the iPhone when the iPhone is locked or asleep, unless the Watch is locked, so a quiet phone may not mean a missed alert.
- iPhone, check for a Focus: open Control Center and look at the Focus control. Tap the active Focus to turn it off. Apple also suggests checking whether your iPad or Apple Watch is in a Focus, especially if 'Share Across Devices' is on.
- iPhone, let WhatsApp through: go to Settings > Focus, tap the Focus, tap 'Apps', make sure 'Allow Notifications From' is selected, tap 'Add Apps', choose WhatsApp and tap 'Done'. Apple says apps can't be allowed this way in the Driving Focus.
- iPhone, Scheduled Summary: go to Settings > Notifications > Scheduled Summary. Either turn it off, or turn WhatsApp off under 'Apps in Summary'.
- Android, check for Do Not Disturb: swipe down from the top of the screen and look at 'Do Not Disturb' in Quick Settings.
- Android, check schedules: go to Settings > Modes and look at each mode, such as Bedtime or Driving. Its notification filters decide which people and apps get through. Some of these steps need Android 14 or later, and older phones keep the schedule under 'Sound & vibration'.
- Android, let WhatsApp through: in WhatsApp's notification settings on the phone, turn on 'Override Do Not Disturb'.
Cause 3: Android battery optimization is keeping WhatsApp asleep
If alerts arrive late, in bursts, or only after you unlock the phone, look here first. Google says features that save battery can delay or block notifications, that Adaptive Battery may delay notifications, and that with the 'Restricted' setting some notifications might be delayed. WhatsApp says battery restrictions can block its notifications and asks you to exclude it from them.
These are the paths WhatsApp lists, and labels can vary by software version:
- Samsung: Settings > Battery and device care > Battery > Background usage limits > Never sleeping apps, then add WhatsApp.
- Xiaomi or Redmi (MIUI): Settings > Battery & performance > App battery saver > WhatsApp > 'No restrictions'.
- OnePlus: Settings > Battery > Battery optimization > WhatsApp > 'Don't optimize'.
- Oppo or Realme: Settings > Battery > More battery settings > Optimize battery use > WhatsApp > 'Don't optimize'.
- Huawei or Honor: Settings > Battery > App launch > WhatsApp > 'Manage manually', then turn all the toggles on.
- Other Android phones: Settings > Battery > Battery optimization > WhatsApp > 'Don't optimize'.
- Pixel: Google's path is Settings > Apps > See all apps > WhatsApp > 'App battery usage' > 'Allow background usage'. 'Unrestricted' removes the background limits. Google recommends 'Optimized' for most apps, so make this exception for the apps you can't afford to miss.
Cause 4: Background data or Low Power Mode is limiting the app
If alerts work on Wi-Fi and stop on mobile data, suspect a data limit. On Android, Google says that with Data Saver on, most apps and services get background data only over Wi-Fi.
On iPhone, Apple lists turning off Background App Refresh among the things Low Power Mode does. Apple's list doesn't mention notifications, so treat this as something to rule out, not a certain fix. Do the same with quitting the app: Apple says an app you quit from the app switcher might not be able to run or check for new content until you open it again.
- Android, background data: go to Settings > Apps > WhatsApp > 'Mobile data usage' and turn 'Background data' off and on again, as WhatsApp suggests.
- Android, Data Saver: go to Settings > 'Network & internet' > 'Data Saver' > 'Unrestricted data' and turn WhatsApp on. These are Pixel menu names; other phones may differ.
- iPhone, Low Power Mode: on iPhone 15 and later go to Settings > Battery > Power Mode, and on iPhone 14 and earlier go to Settings > Battery. Test with it off. Apple says it switches off once the phone reaches 80% charge, and that on devices with Adaptive Power turned on, it can switch on by itself below 20%.
- iPhone, background refresh: go to Settings > General > Background App Refresh, and make sure it isn't set to 'Off'.
Cause 5: The chat or group is muted
If everyone else alerts you and one chat never does, it is usually this. It is also easy to do by accident, and a mute you set on your phone also applies on WhatsApp Web and Desktop.
Groups have an extra setting that catches people out. Even a group that isn't muted can stay mostly quiet if 'Notify for' is set to 'Highlights', which WhatsApp says only alerts you for mentions, replies, messages from contacts and other relevant messages.
- Open the chat, tap the person's or group's name, then tap 'Notifications'.
- Check whether 'Mute' is on, and turn it off on the same screen.
- In a group, set 'Notify for' to 'All' if you want an alert for every message.
- A muted group still notifies you for mentions and replies, so an occasional alert doesn't rule out a mute.
Cause 6: The problem is on a linked device
A tablet or second phone linked to your account follows its own settings, so fixing your main phone does nothing for it. WhatsApp's advice is to repeat the checks on that device.
- On the linked device, allow notifications for WhatsApp, allow background data, and exclude it from battery optimization.
- Turn your primary phone back on or connect it to the internet if it has been off or offline for several days. WhatsApp says this may help.
- Check you are still linked. WhatsApp says linked devices may be logged out if your primary phone is unused for over 14 days. A logged-out device has to be linked again.
- If it still stays quiet, log the linked device out and link it again, or reinstall WhatsApp on it.
How to keep it from coming back
These settings can change quietly, through a new phone or a Focus schedule you forgot about. A short routine catches them.
- After a phone update or a move to a new phone, send yourself a test: lock the phone and have someone message you.
- Look through your Focus or Modes schedules every so often, and remove the ones you no longer use.
- Open WhatsApp on your primary phone regularly if you rely on linked devices, well inside the 14-day limit.
- If a missed message costs you money, don't rely on a single alert. Check the app at set times during the working day.
If customers reach you on WhatsApp
A setting can always slip again, so it helps if WhatsApp isn't the only way in. A free OneSol page gives customers one link to reach you on WhatsApp and elsewhere, and it can collect emails so you can still contact them if an alert never arrives.