"Hidden City” Ticketing & Why It is So Risky...
Some error fare scams involve tickets with an extra leg that is added on to the main ticket. Many of these involve what is known in the travel industry as “hidden city” ticketing. This is specifically prohibited by almost every airline in the contract you enter into when you buy a ticket from them.
So let’s say you see a $200 round trip ticket from Boston to Sao Paulo. But at the bottom of the page you see the blog is saying "This ticket actually ends in Toronto but just get off the plane in Boston and ignore the Toronto leg... Oh, and don’t call the airline…”
This is NOT a mistake on the part of the airline. It is a deal that the travel blog or website created by using a “hidden city” and taking advantage of what travel agents call an “illegal routing”. So your ticket is not Boston to Sao Paulo then Sao Paulo to Boston. Instead, it is Boston to Sao Paulo then Sao Paulo to Boston and then Boston to Toronto. The hidden city (Toronto) may have lowered the price but with this ticket the airline has no obligation to take you back to Boston. In fact, their obligation is to take you to Toronto! Which is why these sites tell you “Don’t check bags…”. If you check your bags that’s where they will end up — Toronto instead of Boston!
But here's why this is risky: Let’s say your flight from Sao Paulo to Boston is cancelled due to bad weather or mechanical problems. The airline’s computers see your destination as Toronto -- and so does the gate agent. So, when they reschedule your flight, that's where they will take you -- and you may not go anywhere near Boston!
Once in Toronto it will be your problem to get back home — so carry your passport — but don’t expect the discount travel site or blogger to explain this -- they couldn't care less!