Have you always paid using an Acceptgiro form?
Then you don't need to do anything to end your library membership. If you do not pay for the new year, your library card will be blocked. You will receive an automatic reminder but you can simply ignore it. You can no longer borrow anything once your library card has been blocked.

Do you pay by direct debit?
Then you will need to withdraw the payment authorisation with an intrekking machtiging form which you can obtain directly from your bank, or online from your bank’s website. You can hand in the completed form at the library service desk. Or you can send it to the library:

Bibliotheek Den Haag
t.a.v. de afdeling Financiën
Postbus 12653
2500 DP Den Haag

We will then cancel the direct debit for you. 

Do you still have items at home or unpaid fines?
If you end your library membership remember to check in ‘Mijn bibliotheek’ whether you still have borrowed items at home, or if you have any outstanding debts to be paid.