Can i change my pay as you go sim to a contract sim?

I just got an iPhone and I was using an android phone before but when I got the iPhone I bought a new sim card and to test the iPhone and it is working so can I change it to a contract sim card.

Of course!
You now have the freedom to pick which provider you want to go with. Make sure its the right one for you as contracts are typically 2 years.

Simply pop into the store of the chosen company and they'll be able to set it up for you. You'll need a micro sim! Xx

Yes you can change any pay as you go sim into a contract sim, just go to your network provider (3, EE) etc, and ask about the tariffs for your phone.