Signal uses your phone's internet connection for all private communication. The most common reasons why you can't receive messages when your phone is connected to the internet is that you have restricted Signal's internet access or it can not run or transmit data in the background.
- Re-enable application permissions for Signal on your phone.
- Disable or modifying settings for your third-party app, VPN, or firewall that is limiting Signal's connection to the internet.
- Allow Signal to work in the background and when your device has low battery. Some phones list this as doze mode, data saver, battery optimization or power management settings.
See additional steps for:
Android
Basic Troubleshooting
- Update to the latest version of Signal Android and enable all application permissions as listed above.
- Update the Google Play services app on your phone and enable all application permissions.
- Allow Signal to autostart and work in the background. Enable phone specific settings.
- Check OS-specific settings.
Why can I send Signal messages but not receive them?
If your messages appear to be 
Sent, but you do not receive Signal messages, try to re-register using the steps below.
- In Signal, tap your profile
> Advanced > Signal messages and calls. - Choose OK to confirm.
- Tap Signal messages and calls a second time to re-register.
- Enter or edit your phone number.
- Tap Register.
- Complete the registration process.
- Send messages on Signal.
My insecure SMS/MMS does not arrive, what do I do?
Messages to your SIM card arrive through your mobile plan, are insecure, and need your phone to be connected to your mobile network.
- Confirm you have SMS (text) or MMS (Group and media) as part of your mobile plan and that you are connected to your mobile network.
- Enable Signal Settings > SMS and MMS > 'WiFi Calling' compatibility mode and try again.
Why are insecure messages going to my other SMS app?
In addition to supporting end-to-end encrypted messages and calls with other Signal users, Signal Android can be configured as your default SMS/MMS app. If you recently updated your Android OS, temporarily remove Signal as your default messenger and set it back. In Signal, tap your profile > SMS and MMS > tap SMS Enabled to select another app then tap SMS Disabled to set Signal as your default SMS app again.
iOS
Basic Troubleshooting
- Update to the latest version of Signal iOS and enable all application permissions as listed above.
- Confirm that you have enabled notification permissions for Signal.
- iPhone Settings
> Signal > Notifications > Allow Notifications. - Enable Sounds, Badge App Icon, and Show on Lock Screen.
- For sound notifications,
- Enable sounds as listed in step above.
- Take your device off silent/vibrate mode where the outside switch is not showing orange.
- Enable message send sounds in Signal Settings
> Notifications.
Can you send messages but not receive them?
iOS users will want to submit a support request.
Desktop
Basic Troubleshooting
- If are on Wi-Fi that has firewall restrictions in place, contact the network administrator.
Can you send messages but not receive them?
Dekstop users will want to submit a support request.