Q: iPhone 6 suddenly says no service/searching

HEllo

The other day I was having an SMS exchange and suddenly my messages started bouncing. I noticed it said no service. So I turned my phone off, and when it rebooted it also said this. I turned it off, took the SIM out for 5 minutes, then it went to "searching...".

Thinking it was a network outage, I went to my sisters area. There was no service there so I went to an O2 shop who declared my SIM to be working after checking it in their device. No other SIMs worked in the phone.

I took the thing home and restored it as per some suggestions. This also has done nothing.

I can connect to wifi okay. I have not dropped it as far as I know.

Im in the UK and have had this phone for 18m so I don't have normal warranty.

If this is a spontaneous hardware failure am I still able to claim, or am I screwed?

Also, any suggestions?

THanks in advance.