Originally Posted by
A_flyer
Read carefully what I wrote, it's not a stamp, it's indicated in the tax details of the ticket.
How you think they know you pay or not the travel tax at the check-in? just by looking at the ticket... it's indicated! but of your you will not see a phrase saying "this passenger have already paid the travel tax". But theres' a code telling this.
If you pay it at the airport at the travel desk countrer, you get a receipt you have to give at check-in. That's why you need to pay it before check-in.