I'm getting the iphone 4s tomorow

Hi, i'm getting the iphone 4s tomorrow and i was wondering if you could tell me if i could put the sim i have used for my blackberry into the iphone4s or does it need to be different

If the Sim on your blackberry is the big version then you can't put it in the 4s, however if it is the small micro Sim then yes, it will go in.

If your sim is a "Micro"-sim, then you don't have to change it. Even if you plan to get an iphone 5 or 5s later on, you can cut your sim to be a "Nano-sim" and use it with the newer phone (there are sim-cutters you can buy from ebay for less than 10$). The link below is a good photo guide (from Apple) about the size of different sims.

Blackberry phones take a standard sim card, iphone 4s needs the micro one so no it won't fit and please don't try to cut it down, many people do this with no problem but others do it and end up getting it stuck, not worth it when you can simply ask your provider for a micro sim and they will give you one.

All networks provide micro sims, they are not hard to get and are usually completely free so just call and ask or go into the shop and ask there.