Can i retain my phone number if i switch to iphone 5?

Currently i'm using a normal phone with normal sim card

Just cut your sim to a nano sim

Yes you can. Anybody can retain their phone number, your options are taking a risk and cutting your sim card down or just going and getting a different sim from your provider and having them switch the phone number. I also highly recommend waiting for the iPhone 5S it'll be released within a few weeks. Apple announces it on Tuesday.

Yup you can. You have two options:

1.cut it yourself
2. If you are on contract call the mobile network shop and they will send you one (that's what i did)