Trimmed sim card doesn't fit in iPhone 5?

So yesterday I went to a phone shop to cut my simcard for an iPhone 5 but when i tried it at home it didn't fit. If I want it to fit I need to cut a little bit of the gold part of my sim? Can I do that? Or do I need to buy a new sim card?

IP5 need nano Sim. Just cut the same around around the golden part without damaging golden part.
If, its not working just visit network shop they will provide you nano sim and they will transfer all your contact to your new sim.