I have a contract phone with the network 3 but I have bought an iPhone 4?

I was wondering I I cut my normal contract sim down to micro size will the aim then need unlocking to work in the iPhone. It work now In the contract phone but will it need unlocking to work in that phone thank you

I really do not know why anyone would buy an iphone4 now its tech is nearly 3 years old (I see this a lot, the latest iphone is NOT bought but the "affordable" iphone despite the fact that most phone maker have BETTER "specced" and CHEAPER, phones

All iPhones are just overpriced and to justify the above just one article here on YOUR iPhone4 which came out in June 2010 and which APPLE INVENTED CAMERA FLASH for this phone as before the IP4 NO iPhone had camera flash, so 3rd and 4th paragraph http://www.itproportal.com/2012/09/06/8gb-iphone-4s-version-be-introduced-iphone-5-launch/#ixzz2E

This is a bad purchase as APPLE only support the last 3 iPhones.
On 12/09/2012 releases IP5 drops IP3 GS, later this year releases IP6 (IP5S? Name ) drops IP4 and with that IP4 price falls.

Your answer is; Cutting is ARTS & CRAFTS scissors yada yada yada… The IP4 needs to be UNLOCKED so you can use it on 3 unless is is already a "3" iPhone4

All you have to do is go into a "3" store and they will provide micro sim, 3 deactivates current sim card activates microsim, nothing changes. It take minutes cutting is hit and miss