Would a US bought iPhone work with a UK sim card?

Would a US bought iPhone work with a UK sim card?

You may need to get it unlocked first, and given that US SIM cards are the same size as UK ones, then yes it should be okay.

Best thing would be to contact your current provider. If you need a uk SIM card contact www.simdepot.co.uk. You can email them
On trade@simdepot.co.uk and they'd send you out a free uk SIM card

Yes, a US bought iPhone will work with a UK sim Card if it is unlocked. To unlock your phone you can make use of http://www.simpleunlocking.com/apple-iphone/rs16wp9/ where they unlock your phone with the help of remote unlocking service.
After getting remote unlocking service you can make use of http://www.mobileunlockguide.com/apple-iphone where they provide you with free unlocking instructions.