iPhone Can't Send or Receive Texts or Says "Not Delivered"? How to Fix It

A message won’t go through — you see a red exclamation point with “Not Delivered,” or texts simply aren’t arriving on your iPhone.

Why: iPhone sends two kinds of messages: blue iMessage (over Wi-Fi or cellular data) and green SMS/MMS/RCS (over your carrier’s network). A failure usually means one of those paths can’t connect right now — no signal, iMessage temporarily unavailable, or the wrong number/email set to send and receive. Try these in order.

Fix 1: Resend, then fall back to a text message

1. Check you have signal or Wi-Fi: look at the status bar, or open Settings > Cellular and Settings > Wi-Fi.
2. On the failed message, tap the red exclamation point, then tap Try Again.
3. If it still won’t send, tap the red exclamation point again and tap Send as Text Message. This routes it over SMS instead of iMessage (it’ll turn green).
4. To make this automatic in future, turn on Settings > Apps > Messages > Send as Text Message so failed iMessages fall back to SMS on their own.

Fix 2: Toggle iMessage off and on, then restart

1. Go to Settings > Apps > Messages and turn iMessage off. (On older iOS: Settings > Messages.)
2. Restart the iPhone (power off, wait, power on).
3. Return to Settings > Apps > Messages and turn iMessage back on. A spinning gear next to your number is normal while it re-registers.

Fix 3: Check Send & Receive addresses

If people text you but the replies never arrive — or your sends fail to one specific person — the wrong address may be selected.

1. Open Settings > Apps > Messages > Send & Receive.
2. Under You can receive iMessages to and reply from, make sure your phone number and/or email are checked.
3. Under Start new conversations from, pick the number or email you want shown as the sender.

Fix 4: Update iOS, check storage, then contact carrier or Apple

1. Install any update: Settings > General > Software Update.
2. If photos or videos won’t send/receive, free up space — a full device can block MMS. Check Settings > General > iPhone Storage.
3. If SMS/MMS still fails (green messages), the issue is on the carrier side — contact your carrier and confirm your plan supports texting and group messaging.
4. If iMessage (blue) still fails everywhere, contact Apple Support.

FAQ

What does the red exclamation point mean? Your message didn’t send. Tap it, choose Try Again, and if that fails, Send as Text Message to route it over SMS.

My texts to one person fail but others are fine. That person may have changed phones or turned off iMessage. Tap the red exclamation point and Send as Text Message to reach them over SMS.

I get texts but can’t send any. Toggle iMessage off and on (Fix 2), confirm your number is checked under Send & Receive, and make sure you have a working signal.

Sources: Apple Support — If you can’t send or receive messages on your iPhone or iPad