Welcome to the AC Hotel Boston Downtown! Please use this link to book your hotel room. You may cancel your reservation for no charge before 11:59 PM local hotel time 2 days before arrival. Please note that we will assess a fee of the first night room and tax if you must cancel after this deadline. If you have made a prepayment, all or part of your prepayment will be retained. If not, the card on file will be charged. Deposit due day of arrival: First night room and tax