I would recommend not to use viator as the company is totally fraud. I booked a ticket from viator.com and now I am suffering with the lead travelers name change, when I booked they said they will be able to change lead travelers name at the later date but now they are not supporting. Their checkout page suggest, "For security purposes the lead traveler's name must match the name on the credit card used for this booking, and the credit card used for this booking must be presented at the time of travel and/or redemption. If the lead traveler/card holder is not traveling, that is OK but you must contact our customer care staff after completing the purchase to request a change." I have emailed them several times but no reply whatsoever. Seems like trip-advisor is ruining its own reputation. NEVER EVER VIATOR OR TRIPADVISOR.