Originally Posted by Koby

There have 2 types of one-day tickets:

* The "Jump" 1 day ticket is valid for all STIB lines (except the bus lines to the airport). It's also valid for the bus lines operated by De Lijn (flemish), TEC (walloon) and on trains, but only within the borders of Brussels (which excludes the airport). So adding the Diabolo fee is not enough, you'll have to buy a ticket to the airport.

* However, a good alternative is the "Discover Brussels" 24h card. It's only valid on the STIB lines (so no trains), but this one does include the 2 bus lines to the airport (12 and 21).

Both cards cost the same: 6€.