No sim after upgrading to iOS 15

If you see No Service or Searching on your iPhone or iPad

1. Check your coverage area. Make sure that you're in an area with cellular network coverage. ... 
2. Restart your iPhone or iPad. Restart your device. ... 
3. Check for a Carrier Settings update. ... 
4. Take out the SIM card. ... 
5. Reset your Network Settings. ... 
6. Update your iPhone or iPad. ... 
7. Contact your carrier. ... 
8. Get more help.

If you see No Service or Searching on your iPhone or iPad ...

Remove your SIM card from the SIM card tray and then put the SIM card back. ... Make sure that the SIM tray closes completely and isn't loose. If you use a SIM tray from a different model iPhone, iPad, or from another phone manufacturer, it might not fit properly.

If you see 'invalid SIM' or 'no SIM' on your iPhone or iPad ...

Learn what to do if you see a SIM not supported alert.

I’m using XR model and 2uel SIM card I’m using on my phone eSim+ Nano Sim. After updating ios 15.0.2 my mobile network switching like every second shows no service and immediately getting network coverage ( doing flight mode on + restarting phone). I check with my cellular networks as well.

I updated my iPhone Xs Max with iOS 15.2 today and the SIM card stopped working - had to get a new one. It would have been nice to know the update might stop my phone from working before I did the update.

I am using iPhone 12 and after updating to 15.1.1 my sim got inactive.The same we faced with my brothers iPhone 13 pro.

kindly reslove the issue.

Check whether there is an update of carrier settings on your iPhone. You can also try to remove the SIM from the SIM Card tray and then put it back.

Don’t give bug iOS update for its apple huawei is better than apple

I am using iPhone 11 and my daughter is using iPhone 12, both running iOS 15+, we found that eSim just doesn't work - can't activate at all !! It is so bad that Apple made such a serious bug !!

I really don't want to do factory reset ...