General
There are the two classic choices for mobile phone:
- a prepay card.
- a contract.
There are plenty of companies offering these services so you can search which one fits better your needs.
Prepay Card
In order to buy a prepay sim card, you just need your passport or permit of residence. This will be your first choice before signing a contract.
Contract
The contracts are for at least one year and you need to have your permit of residence. If you buy a contract on the same company as your prepay, you can keep the same number and sim, without having to pay again. There are very reasonable contracts for young people, so you will most probably find the contract better than the prepay.