How do you transfer numbers to a new mobile phone without having to put them in from scratch?

I am buying a new mobile phone on a different network to the one I have . Can I put the little card thing into the new one so I dont have to type all the numbers in again if so how do I do it?How do you transfer numbers to a new mobile phone without having to put them in from scratch?
If your phone uses a sim card, then you should be able to transfer the numbers to the sim card. If it uses a data card (like a MicroSD card), you can store them there, as well. You can also use the various phone tools/suite packages from the manufacturers of the phones in question to use a computer to transfer the information. In addition, some phones will allow you to connect via Bluetooth to transfer files from one phone to another. It's all dependent on the kinds of phones involved in the information exchange.How do you transfer numbers to a new mobile phone without having to put them in from scratch?
you can take your old phone or SIM card down with your new phone, and they can transfer the numbers for you.