The block contains 10 single tickets. The pre-printed press version is stapled together and it is available only in blocks. The unstapled block issued by BKK on thermopaper is available in three versions: one contains a cover and 10 individual single tickets with the price printed only onto the cover. The second version consists of 10 individual single tickets without cover, having the price and the date of purchase printed on each. The third version also consists of 10 individual single tickets without cover, having the year of purchase and the price printed on them. The tickets (regardless of block type) are valid for travel separately as well, for a single uninterrupted trip without 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. Validity period is 80 minutes after stamping, while it is 120 minutes on night services. During the period of validity, transfers are allowed only between the metro lines (M1, M2, M3 and M4).
Apart from that, transferring between lines requires another ticket to be validated! Trip interruptions and return trips are not permitted. On metro lines M1, M2, M3 and M4 the ticket must be validated before the start of the trip, on the rest of the lines immediately after boarding or after the vehicle has departed. 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. Validity period is 80 minutes after stamping, while it is 120 minutes on night services. Please show and hand over your ticket if requested by the inspector.
Please find more information here on the refund rule.