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How to Fix a Phone That Will Not Send Text Messages

2026-10-13 · 8 min read

You type a message, hit send, and it sits there with a spinning icon, then fails. A red exclamation mark appears next to the message, or the app shows Not Delivered. You can receive texts from other people but your outgoing messages will not go through, or all texting is broken in both directions. Text message failures happen because of network issues, incorrect message settings, a full message storage, carrier problems, or a SIM card issue.

Check the basics first

Signal strength

• Text messages (SMS) require a cellular connection to send. Check the signal bars at the top of the screen. If you have no signal or very weak signal (one bar), move to an area with better reception and try again
• If you are in a building with poor reception, move near a window or go outside to test. Concrete and metal walls significantly reduce cellular signal

Airplane Mode

• Make sure Airplane Mode is off. Even if you turned it off earlier, double-check — Airplane Mode disables all cellular communication including SMS
• Quick fix: toggle Airplane Mode ON, wait 10 seconds, toggle it OFF. This forces the phone to reconnect to the cell tower and re-register for messaging services

Restart the phone

• Power the phone off completely, wait 15 seconds, power it back on. A restart clears stuck messaging processes and forces the phone to re-register with the carrier's messaging system. This alone fixes the problem in many cases

Check message settings

Android

1. Open your messaging app (Google Messages, Samsung Messages, or your default SMS app)
2. Tap the three-dot menu, Settings
3. In Google Messages: check that Chat Features (RCS) is configured correctly. If RCS is having issues, you can disable it and fall back to SMS. Settings, Chat Features — toggle off Enable Chat Features, then try sending a regular SMS
4. Check the Message Center number (also called SMSC): this is the carrier's server that routes your text messages. If it is incorrect or blank, messages cannot send. The setting is usually under Settings, More Settings, Text Messages, Message Center (varies by phone). Contact your carrier for the correct SMSC number if you need to enter it manually

iPhone

1. Settings, Messages — make sure iMessage is toggled On (for iMessage) and MMS Messaging is toggled On (for picture messages and group texts)
2. If iMessage messages fail (blue bubbles), the issue may be iMessage-specific. Toggle iMessage Off, wait 10 seconds, toggle it back On. This re-registers your phone number with Apple's iMessage servers
3. If only green bubble (SMS) messages fail but blue bubble (iMessage) works, the issue is with your carrier's SMS service, not iMessage. Check carrier settings: Settings, General, About — if a carrier settings update is available, install it
4. Check the Send as SMS toggle: Settings, Messages, Send as SMS — this should be On so that if iMessage fails, the message automatically falls back to SMS

Check if it is SMS, MMS, or both

SMS (text only), MMS (pictures and group messages), and RCS (enhanced chat) use different systems. Identifying which type fails helps narrow the cause:

• SMS fails but MMS works: The SMSC number may be incorrect, or there is a carrier-side SMS routing issue. Contact your carrier
• MMS fails but SMS works: MMS requires mobile data to send (even a small amount). Make sure mobile data is turned on. MMS also requires correct APN settings — see the APN section below
• Group texts fail: Group messages are sent as MMS, not SMS. Same fix as MMS — mobile data and APN settings must be correct
• Picture messages fail: Also MMS. Additionally, very large images may exceed the carrier's MMS size limit (usually 1 to 3 MB depending on carrier). The messaging app should auto-compress, but if it does not, try sending a smaller image

Fix MMS and APN settings

MMS messages require correct APN (Access Point Name) settings. If these are wrong, MMS silently fails:

Android

1. Settings, Network and Internet (or Connections), Mobile Network, Access Point Names
2. Tap the three-dot menu and select Reset to Default. This restores your carrier's default APN including the MMS gateway and MMSC URL
3. If no default is available, search your carrier's website for the correct APN settings and enter them manually. Key MMS fields: MMSC (the MMS server URL), MMS Proxy, MMS Port

iPhone

• iPhones manage APN settings through carrier settings updates. Settings, General, About — install any available carrier settings update
• If MMS still does not work: Settings, Cellular, Cellular Data Network — check that the MMS fields are populated. If blank, contact your carrier for the correct values

Check for a blocked number

• If messages fail to only one specific person, your number may be blocked by that person. A blocked number can sometimes still send messages that appear sent on your end but are never delivered. There is no way to confirm a block from the sender's side with certainty
• Alternatively, the recipient may have a full message inbox (common on older phones), their phone may be off, or their number may be disconnected

Check message storage

• If the phone's storage is full, the messaging app may not be able to save outgoing messages and will fail to send them
• Check storage: Settings, Storage (Android) or Settings, General, iPhone Storage. If storage is nearly full, delete old messages, photos, or apps to free space
• In the messaging app, delete old conversation threads with lots of photos and videos — these consume significant storage space

SIM card issues

• A loose or damaged SIM card can cause intermittent messaging failures. Power off the phone, remove the SIM card, inspect it for damage, clean the gold contacts with a dry cloth, reinsert it, and power back on
• If you have a very old SIM card (more than 5 years), the card may be failing. Visit your carrier store for a free SIM card replacement — they transfer your number to the new SIM
• For eSIM users: make sure the correct line is selected for messaging. Settings, Cellular (iPhone) or Settings, SIM (Android) — check which line is set as the default for SMS

Carrier-specific issues

• Account balance (prepaid): Prepaid accounts that run out of credit cannot send texts. Check your balance through the carrier app or by dialing the carrier's balance check code
• Short code messages blocked: Some carriers block short code messages (5 or 6 digit numbers) by default. If you are trying to text a short code for a verification or subscription, contact your carrier to enable short code messaging
• Carrier outage: If texting suddenly stops working, the carrier may have a messaging system outage. Check DownDetector or the carrier's social media for outage reports

Third-party messaging apps

• If you are using a third-party messaging app (WhatsApp, Telegram, Signal, Facebook Messenger), the issue may be app-specific rather than a carrier SMS issue. These apps use data (Wi-Fi or mobile data) rather than the SMS system
• If a third-party app is not sending: check your internet connection, update the app, clear the app cache (Android: Settings, Apps, select the app, Storage, Clear Cache), or reinstall the app
• Make sure the default SMS app is set correctly: Android sometimes changes the default messaging app after an update. Settings, Apps, Default Apps, SMS App — make sure your preferred app is selected

Text message repair in Marion

If your phone will not send text messages and the troubleshooting above did not fix it, Marion Phone Repair can diagnose whether the issue is a SIM card problem, a carrier configuration issue, a software glitch, or a hardware failure affecting the cellular radio, and restore your ability to send and receive messages.