When you are moving to the Netherlands and want to have a dutch mobile phone number you can choose between a prepaid or a contract. The most dutch mobile companies are known in the rest of the world like Vodafone and T-mobile. If you want a contract you will need valid proof of identity (not a driving licence), official dutch bank statement and proof of bank account. A contract can be for 1 year or 2 years and with or without a mobile phone.
No extra charge for making or receiving calls while roaming. You have a dutch contract with a moble service provider which includes roaming. Thanks to the EU "roam like at home" rules you don't have to worry about paying a surcharge for any calls to EU numbers he makes or receives during a business trip to an European Country.
KPN is market leader in the Netherlands. They offer all the new phones and give discount when combining their services with tv/internet. (our favorite)
Vodafone offers all the new phones.
T-mobile offers a wide range of state of the art phones and a combination of pre-paid and different contracts.
Ben offers older type phones but is therefore more afforable.