Budapest has an international airport, and the city can be reached by shuttle bus (provided by the airport, the order can be made upon arrival or on-line prior to travel) or by taxi in about 30 minutes to one hour. Reliable taxi services are available at the airport. Prices are usually below EUR 30 from the airport to the city. Major railway stations are in the city and all of them are beside metro stations.
Accessibility to the Congress Venue from the Liszt Ferenc International Airport:
After arrival to Budapest at Liszt Ferenc International Airport in Budapest, you should take official airport taxis. For any taxi ride within Budapest, it is strongly recommended to use officially authorized taxis: Főtaxi: (+361) 222-2222, City Taxi: (+361) 211-1111, Tele5taxi: (+361) 555-5555. Estimated taxi fare: 30 EUR (one way)
By shuttle minibus:
At the airport, you may also take the minibus. The fixed price for the Airport Minibus Service is about 15 EUR (return ticket is 20 EUR), which will take you to any destination in Budapest and also pick you up at your hotel for your return flight.
Public transportation between the airport and the hotels/congress venue is less expensive (3 Euro for a one-way trip) but also less convenient, with at least 3 transfers.
http://www.bud.hu/english - Airport
http://www.bkk.hu/wp-content/uploads/2012/11/200E_bejutasi-taj_2012-09-17.pdf - Airport bus information
http://www.airportshuttle.hu/en/ - Airport Shuttle
http://www.bkv.hu/en/ - Public Transportation in Budapest