The citizen service number (BSN) is a unique personal number allocated to everyone registered in the Municipal Personal Records Database. Your citizen service number is also on your passport, driving license and identity card. You will automatically receive a citizen service number when you register your details at city hall.
Public authorities can use the citizen service number to retrieve your details. Your citizen service number is the only number you will need in your dealings with public authorities. The BSN number is used in for example the healthcare sector (for your health insurance), the education sector (school registration) and tax office (tax return).