Registration at Town Hall
If you are planning on staying in the Netherlands for four months or longer, you will need to have yourself registered as a new inhabitant of the town where you are living. For this registration process you will have to go to the local town hall. If you are staying in Leiden you have to call the local town hall (14071) to make an appointment to register. You can also take a look on the website of the municipality.
Citizen Service Number
After you have completed your registration at the local town hall, you will receive a citizen service number ( burgerservicenummer, BSN‚). You need to have this number if you take a job alongside your studies or if you are planning on doing an internship in the Netherlands.