3 network - a question regarding SIM swapping

[RMCF]

I am currently looking for a new provider after ditching Orange after many years.

I am interested in a £15 per month for life deal with 3, but am not mad on the phones available on the deal.

I don't know much about 3, but would I be able to put my 3 SIM card into any unlocked phone and use it? OR does it have to be a 3G phone?

I do know of course that if I put a 3G sim into a non-3G phone then I will lose the 3G features, but I might be able to live with that. Just want to know if its possible.

[paulmcg]

You can't put the usim in a non 3g phone, but you can put it into an unlocked 3g phone. They do log the fact that you have used the sim in another phone

[RMCF]

Well what if I was to take a phone and then find someone who might want to swap their old K610i with mine?

Would that be possible?

[paulmcg]

you can put the uSIM in any 3G phone as long as it is not locked. You can't put it in a non 3G phone.