1. Check Date & Time.

iMessage will only activate if the Date & Time is set correctly on your iPhone. Here’s how to double check:

1. Open Settings.
2. Tap General.
3. Tap Date & Time.
4. Make sure Set Automatically is switched ON.

2. Update "My Number".

In most cases, re-entering your Mobile Number on your iPhone can resolve issues with iMessage and FaceTime.

1. Open Settings.
2. Scroll down to Apps and tap Phone.
3. Tap My Number.
4. Enter your mobile number, using +44 instead of the first 0.
5. Tap Save.

3. Reset iMessage and FaceTime.

This forces your iPhone to re-register your correct number with Apple's services.

1. Go to Settings > Apps > Messages and switch iMessage OFF.
2. Go back to Settings > Apps > FaceTime and switch FaceTime OFF.
3. Restart your iPhone completely (turn it off and on).
4. Once it's back on, go back to Settings > Apps and turn both iMessage and FaceTime back ON.

You might see a "Waiting for activation" message for a few minutes. This is normal. Check Settings > Apps > Messages > Send & Receive to see if your number has a tick next to it.

4. Remove old or inactive SIM profiles.

Sometimes, your phone can get confused if your SIM or eSIM from your previous network provider is still installed. Here’s how to check:

• If you used a physical SIM card with your old network:
  Turn off your iPhone, open the SIM tray, and ensure only your iD Mobile SIM is present.
• If you used an eSIM with your old network:
  Open Settings > Mobile Service. If you see an old eSIM profile from your previous network, tap it and then tap Delete eSIM.
• If you requested a replacement iD Mobile eSIM:
  We recommend deleting your old eSIM profile first, if you're able to. Don't worry if you can't do this (for example, if your phone was lost, stolen, or has already been reset).

5. Force restart your iPhone.

• If you’re using a physical SIM card, remove your iD Mobile SIM, but pop your SIM tray back into your iPhone.
• If you’re using an eSIM, open Settings > Mobile Service, select your iD Mobile eSIM, and switch the Turn On This Line toggle to OFF.

Now, force restart your iPhone:

1. Press and quickly release the Volume Up button.
2. Press and quickly release the Volume Down button.
3. Press and hold the Side Button (power button) until you see the Apple logo.

Once your iPhone restarts, connect to a stable Wi-Fi network and wait 30 minutes. After this time, re-insert your iD Mobile SIM or toggle your eSIM back ON.

6. Reset Network Settings.

As a last resort, perform a Network Settings Reset on your iPhone. Here’s how:

1. Open Settings.
2. Tap General.
3. Tap Transfer or Reset iPhone.
4. Tap Reset.
5. Tap Reset Network Settings.

1. Reset RCS Chats.

Your Google Messages app might be holding onto the temporary number. Resetting the chat features usually fixes this.

1. Open Messages.
2. Tap your profile icon or More Options (three dots).
3. Tap Settings (or Message settings).
4. Tap RCS chats.
5. Toggle RCS chats to OFF.
6. Restart your phone.
7. Open Messages again and turn RCS chats back ON.

2. Clear app cache.

If the above didn't work, clear the data for the Messages app.

1. Open Settings > Apps.
2. Find and tap Google Messages (or Messages).
3. Tap Storage.
4. Tap Clear Cache.

3. Remove old or inactive SIM profiles.

Sometimes, your phone can get confused if your SIM or eSIM from your previous network provider is still installed. Here’s how to check:

• If you used a physical SIM card with your old network:
  Turn off your phone, open the SIM tray, and ensure only your iD Mobile SIM is present.
• If you used an eSIM with your old network:
  Open Settings > Connections > SIM manager. If you see an old eSIM profile from your previous network, tap it and select Remove.
• If you requested a replacement iD Mobile eSIM:
  We recommend deleting your old eSIM profile first, if you're able to. Don't worry if you can't do this (for example, if your phone was lost, stolen, or has already been reset).

4. Reset Network Settings.

As a last resort, perform a Network Settings Reset on your phone. Here’s how:

1. Open Settings.

2. Tap General management.

3. Tap Reset.

4. Select Reset Network Settings.

1. Reset RCS Chats.

1. Open Messages.
2. Tap your profile icon or the menu button.
3. Tap Message settings.
4. Tap RCS chats and toggle it OFF.
5. Restart your phone.
6. Turn RCS chats back ON.

2. Clear App Cache.

1. Open Settings > Apps.
2. Tap See all apps.
3. Tap Messages.
4. Tap Storage & cache.
5. Tap Clear cache.

3. Remove old or inactive SIM profiles.

Sometimes, your phone can get confused if your SIM or eSIM from your previous network provider is still installed. Here’s how to check:

• If you used a physical SIM card with your old network:
  Turn off your phone, open the SIM tray, and ensure only your iD Mobile SIM is present.
• If you used an eSIM with your old network:
  Open Settings > Network & internet > SIMs. Tap your old network's eSIM and select Erase eSIM.
• If you requested a replacement iD Mobile eSIM:
  We recommend deleting your old eSIM profile first, if you're able to. Don't worry if you can't do this (for example, if your phone was lost, stolen, or has already been reset).

4. Reset Network Settings.

As a last resort, perform a Network Settings Reset on your phone. Here’s how:

1. Open Settings.

2. Tap System.

3. Tap Advanced.

4. Tap Reset options.

5. Select Reset Network Settings.