First departure hits Brussels Airport around 5:30, even on weekends
MIVB/STIB Airport Line 21 is the fallback bus when the train is done for the night or you just missed Line 12. It runs between Brussels Airport (T) and Luxembourg/Schuman area, stopping at key points like NATO and Schuman, and uses regular MIVB/STIB tickets starting at a few euros if you have a MOBIB card or mobile ticket.
At the airport, Line 21 stops on level 0 of the terminal building, just below arrivals in T, in the MIVB/STIB bus area signed for “Brussels City.” Buses pull in every 20–30 minutes in the early morning and late evening, and you board through the front door to validate your MOBIB card or scan a QR-code ticket.
On weekdays, Line 21 usually starts running around 5:30 and keeps going into the late evening, often after 23:00, covering a gap where some trains to Brussels North stop earlier. Weekend timetables stay similar, with service on Saturdays and Sundays so you’re not stuck paying €25–€35 for a taxi into the EU quarter if your Ryanair or TUI flight lands late.
From the airport, the bus reaches NATO in roughly 10–15 minutes and Schuman in about 25–30 minutes, traffic allowing. That puts you close to the EU institutions and within a couple of metro stops of Brussels-Central, De Brouckère, and other central stations, using the same ticket you validated when boarding Line 21 at T.
Tickets bought from a GO vending machine near the stop at level 0 usually cost less than buying from the driver, and many riders load a 10-journey ticket onto a MOBIB card to bring per-trip cost down to around €2.10. Day passes are also valid on Line 21, so one pass covers the airport leg plus metro and tram rides across the city until service ends.
Suitcases fit best in the open standing areas near the center doors, and the buses running to and from BRU are mostly low-floor models with step-free entry from the curb. There’s no luggage rack like on some airport coaches, so keep one bag by your legs and avoid blocking the yellow exit zone if boarding at busy stops such as Schuman during the 17:00–19:00 rush.
One last tip: screenshot the Line 21 timetable and route map from the MIVB/STIB planner before you lose airport Wi‑Fi at T, then stand near the front half of the platform on level 0 so you can board quickly and grab space for bags when the bus doors open.