You must schedule the day and time of the visit at the time of purchase. If you are registered as a customer on this website, you can change the scheduled date an time in your reserved area, subject to availability. 
If you purchase your Ticket-Voucher online, we would request that you present it at the Livraria Lello entrance, whether digital format or in a physically printed. If you do not have proof of the Ticket-Voucher in your possession, we shall not be able to authorise your entry.