You must have these strips stamped when you board, either by using a yellow machine, or by the conductor in front or back of a tram or a bus conductor. To use the machine you fold over the kaart to the line you want stamped, and insert it into the horizontal slot until you hear the "ding." The penalty for not having a valid ticket with stamp is around 30 Euros. And they do check when you least expect it!

The most difficult part of the strippenkaart is figuring out the proper way to stamp it. As you can see in the sample at left, there are 15 spaces for stamps (A 45 space kaart is also available). If you are staying in the same zone, you need to have it stamped two lines down from the last stamp. Note the first row is in red, indicating that would not be valid stamp. Two lines is the minimum.

Now if your trip takes you out of your zone into the next one, you must stamp it 3 lines down. Likewise a trip involving 3 zones would require a stamp four lines down.

If you're not sure how many zones you're going, you can either look on a map which usually has the zones outlined. Or if you're getting on a tram or bus you can tell the conductor your destination, and they'll put the proper stamp. If you know how many zones your trip is, tell the conductor (one zone please) and they'll make the appropriate stamp.

If you're staying in Amsterdam's Centrum, within the outer canal ring, it's all one zone, so you just need to stamp it two lines down.

The stamp is good for one hour for one to three zones, longer if your trip takes you thru more zones. This info is on the back of the strippenkaart. So you could conceivably take a trip somewhere, do what you need to do, and return all with just one stamp! In addition the stamp includes any transfers even if you're getting on another form of transport like bus to metro or tram.

So why bother with this? Well you'll save money and hassle because the strippenkaarts (6.20 Euros for 7 short trips) work out to less than 1 Euro per trip, as opposed to about $1.30 or 1.40 Euros if you pay for each trip separately. You can also pay for your companion(s) using the strippenkaart, just stamp it more times for each person.

If you get to the end of your strippenkaart, and there's just one space left, you can still use that (as every Dutch person would), by stamping that one, plus one line on another strippenkaart. That would equal the required two lines for a one zone trip, so you wouldn't waste it!

If you're a student or senior or get in on some discount plan, you can purchase monthly or yearly discounts, and you'll get a photo ID so you don't need to pay everytime, just flash your card. Discounted strippenkaarts available for those over 65 (with valid ID), students and children aged 4-11. These strippenkaarts have a red color.