If you changed your SIM card for a while and now iMessage and your Apple ID are not working correctly, follow these steps to resolve the issue:

Solution 1: Check Carrier Settings

Ensure that your carrier supports SMS and MMS services, which are required for iMessage and FaceTime activation. Contact your carrier to confirm:

1. Check if your SMS plan is enabled (including domestic and international SMS).
2. If your carrier is not listed in the Apple support articles, ensure that international SMS is enabled for your number.
3. Try sending an international SMS (even just one) to confirm that SMS is working properly on your network.

Solution 2: Verify iMessage Settings

Ensure that iMessage is properly set up on your iPhone:

1. Go to Settings > Messages and ensure that iMessage is turned on.
2. Check that Send as SMS is enabled under the same settings. This ensures that when iMessage isn’t available, your messages are sent as regular SMS.
3. Make sure your iPhone is connected to the internet via Wi-Fi or cellular data. iMessages require a stable internet connection to work.

Solution 3: Sign Out and Back into Apple ID

If you’re unable to sign out of your Apple ID, try these steps:

1. Go to Settings > Your Name > Sign Out.
2. If you’re unable to sign out, try restarting your phone and attempt again.
3. After signing out, sign back in using your Apple ID and check if iMessage and FaceTime activate properly.

Solution 4: Reactivate iMessage and FaceTime with Your Phone Number

To ensure that iMessage and FaceTime are activated using your phone number:

1. Go to Settings > Messages > Send & Receive.
2. Ensure that your phone number is selected under both iMessage and FaceTime.
3. If not, tap on your number to activate it and follow the on-screen instructions to complete the process.

Solution 5: Restart iMessage Activation

If iMessage still isn’t working, try toggling iMessage off and back on:

1. Go to Settings > Messages and turn off iMessage.
2. Restart your phone and then turn iMessage back on.
3. This will attempt to re-activate iMessage using your phone number.

Solution 6: Contact Apple Support

If none of the above solutions work, you may need to contact Apple Support for assistance. There may be an issue with your Apple ID or network settings that requires further troubleshooting.

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