Great until you need an amendment. Requested cancellation 60 minutes after receiving booking confirmation but was denied a refund even though the tour is 3 weeks out. Two separate agents delivered the same canned response that contradicted the tour information itself. After speaking with a supervisor (Alex), she rudely cut me off as I spoke, grew frustrated at the customer, and refused to escalate further. She verified her agents never called the tour supplier. The point of using a travel agent is to leverage their existing relationships with vendors, not disrespect and dismiss customers. Not the experience I was expecting after having used Viator 10+ times in the past. Everything is great as long as you don't have a problem - as soon as you do, good luck garnering support. Not only have you lost a loyal customer, but I am extremely upset with how I was treated (as well as many others after reading similar reviews)