'no service' on iPhone 11 ... but my SIM card works in another iPhone

And you did try to reset your device? This step fixes so many problems, but is often overlooked.

If you have indeed tried this already, I would recommend contacting your Carrier. If your carrier confirms that there's no issue with your account or network, but you still can't connect to a cellular network, please contact Apple Support.

Good Luck!

Hello N_i_k_k_i!

Please read the entirety of this Support Article, to learn what steps you can take to fix this vicissitude: If you see No Service, Searching, or SOS on your iPhone or iPad - Apple Support.

I hope this is helpful. Good Luck!

Same thing has happened to me literally this morning!

My phone (iPhone 11) has decided this morning to sit in SOS / No Service. It was working perfectly fine prior to this.

I've spoken to both Apple and then my provider (TPG) who each say there are no issues on their respective ends and it must be the other (device / service) issue. Diagnostics was run by Apple with no issues on cellular device and no blockages or outages with TPG either.

I've swapped sims with hubby and my sim works fine in his phone but when his sim was in my phone it wasn't working and sitting on SOS / No service.

I've tried resetting network settings, resetting phone, air plane mode, taking sim out to clean, charging phone, leaving it switched off, making sure auto network is on.

ZERO idea what to do next apart from getting a new phone, it's SO frustrating!!