A text not being delivered on an iPhone usually comes down to connection, settings, or an issue on the recipient’s side. Below are the most common reasons and what they typically mean.
iMessage vs SMS behavior
- If the bubble is blue (iMessage) and shows “Not Delivered,” it usually means your phone or the recipient’s device lacks a stable internet connection, iMessage is temporarily down, or there’s an Apple ID/iMessage configuration issue.
- If the bubble is green (SMS/MMS) and does not say “Delivered,” it usually points to a cellular‑network or carrier problem, an invalid number, or your line not being able to send texts (e.g., no service, account issue, or texting blocked).
Common technical causes
- No signal or data: Weak or no cellular signal, or Wi‑Fi/data turned off, prevents both iMessage and SMS from going out or being confirmed as delivered.
- Wrong or unreachable number: A mistyped number, a deactivated line, or texting a landline can stop delivery without a clear error on your side.
- Service or carrier problems: Apple’s iMessage servers or the mobile carrier may be experiencing outages or routing issues, so messages cannot complete the path to the recipient.
Settings and device issues
- iMessage or SMS settings: If iMessage is off, not activated, or “Send as SMS” is disabled, a message may fail instead of falling back to regular text.
- Outdated software or network settings: Old iOS versions, outdated carrier settings, or corrupt network settings can interfere with message delivery until the phone is updated or network settings are reset.
- Storage full or phone glitches: On some devices, very low storage or temporary software glitches can stop messages from sending or being received until the phone is restarted or space is freed.
Recipient-side reasons
- Phone off or no connection: If the recipient’s iPhone is turned off, in airplane mode, has no signal, or is out of data/Wi‑Fi, messages may stay in a pending state and not show as delivered.
- Blocked number: If the recipient has blocked your number, messages you send will not be delivered to their device, and you typically will not see a “Delivered” indicator.
- Device or account changes: If the recipient recently changed numbers, devices, or Apple ID settings, old contact details may no longer be able to receive messages.
What you can try
- Check your signal and Wi‑Fi/data and toggle airplane mode off/on, then resend.
- Confirm the contact’s number or email, and if an iMessage fails, tap and hold the message and choose “Send as Text Message” if available.
- Restart your iPhone, ensure iOS and carrier settings are up to date, and in Settings > Messages make sure iMessage is on and “Send as SMS” is enabled.