If you can't send or receive messages on your iPhone or iPad
Learn what to do if iMessage doesn't work, you can't receive text messages, or you see an alert when you send a message.
Issues with Messages after you set up a new device
Message not delivered
Not receiving messages on a device
Issues with group messages
Issues with photos or videos in messages
If you have issues with Messages after you set up a new device
If you experience issues like conversations in Messages showing up as separate threads or sent messages appearing as green message bubbles instead of blue message bubbles when you set up a new device, update your settings using the following steps:
- Update your device to the latest version of iOS or iPadOS if needed.
- In the Settings app, tap Cellular. Make sure that your phone line is turned on. If you use multiple SIMs, make sure that the phone number you want to use is selected and turned on.
- In the Settings app, tap Apps.
- Tap Messages, then turn iMessage off and then back on.
- Tap Send & Receive.
- Tap the phone number that you want to use with Messages.
If you have issues when you try to receive a FaceTime call after you set up a new device, you can also update your FaceTime settings.
Learn what to do if you can't sign into iMessage or FaceTime
Learn what to do if your messages are green
Learn what to do if you see a Waiting for Activation alert
If you see a red exclamation point
If you try to send a message and you see a red exclamation point
with an alert that says Not Delivered, follow these steps:
- Check your network connection.
- Tap the red exclamation point
, then tap Try Again. 
- If you still can’t send the message, tap the red exclamation point
, then tap Send as Text Message. Messaging rates may apply. 
iMessages are texts, photos, or videos that you send to another iPhone, iPad, iPod touch, or Mac over Wi-Fi or cellular-data networks. These appear in blue bubbles. All other text messages use RCS, SMS, or MMS and require a text-messaging plan. Those appear as green bubbles.
What's the difference between iMessage, RCS, and SMS/MMS?
Contact your carrier if you can't send or receive SMS messages
Learn what to do if you still receive a Not Delivered alert after you try to send your message as a text message
You can set up Messages so that it automatically tries to send messages as an SMS when iMessage isn't available. Go to Settings and tap Apps. Tap Messages, and turn on Send as Text Message.