So do not forget to check-out! - If you've checked in on the bus, tram or subway and you've forgotten to check out, a standard (full) fee of € 4,00 is charged from the Chip Card. - When checked in on the train and you've forgotten to check out, a standard (full) fee of € 20,00 is charged from the Chip Card.

Yes, you absolutely must check out of every tram, bus, and metro in Amsterdam (and throughout the Netherlands). The Dutch public transport system uses a "check-in, check-out" model to calculate distance-based fares. Whether you are using a plastic OV-chipkaart, a GVB day pass, or the newer OVpay system (where you tap your contactless credit card or phone), you must tap your card against the reader near the door both when you board and when you exit. If you forget to check out, the system will charge you a "default fare" (usually €4.00 for trams and significantly more for trains), which is almost always much more expensive than the actual cost of your journey. On trams, the readers are located right by the doors; on the metro, they are integrated into the entry/exit gates. If you realize you forgot to check out after leaving the station, you can often fix the error and request a refund via the official "Uitcheckgemist" website or the GVB app.