Valid for a single trip including one transfer on the whole length of lines 1-99, 101-299, 900-999, M1, M2, M3, M4 as well as on lines H5, H6, H7, H8, H9 only within the administrative boundaries of Budapest. Trip interruptions and return trips are not permitted. The transfer ticket consists of two consecutively numbered sections, both of which must be validated (in the case of older type tickets, the printed number grid at each end of the ticket must be stamped: the first grid when starting a trip, the second grid when transferring), except for transfers between metro lines M1, M2, M3 and M4. When validated by a stamping machine, the total validity period is 100 minutes (on night services it is 120 minutes), with an 80-minute validity after the second stamping. When the second validation takes place at the entrance of a metro station, the validity is 80 minutes even if the whole trip exceeds 100 minutes. If the second stamped validation takes place on a night service, validity is extended an additional 120 minutes. If you need to transfer to a replacement vehicle (e.g. in the event of cancellation, breakdown, track closure), you can continue your journey with the ticket already validated, but you must re-validate the ticket by stamping its end without the number grid with the validator of the replacement vehicle. Please show and hand over your ticket if requested by the inspector. Thermopaper transfer tickets are valid only if both sections are presented for control at the same time.
Please find more information here on the refund rule.