It' just so complicated to figure out how much airlines charge for changing the reservation, e.g. if I want to change my return flight to a later/earlier date. Any hints?
The best answer is to buy a full fare ecnomy ticket that can be changed free of charge. These however are quite expensive. The usual economy fares we buy are a fraction of the price and are heavily restricted. But if you check when you are purchasing what the change fee will be and only change it once, this is the most common option.
Keep in mind that any return ticket can only be changed to return you a maximum of 1 year (364 days actually) from the outbound flight date.
If you're going to be away for more than a year, a return ticket isn't for you. You might consider buying a one way ticket initially.
Keep in mind though that to enter some countries you require proof of onward travel. That is they won't let you in unless you can prove that you have transport booked to get you out of the country before your visa or visa free period expires. You'll simply be put back on the plane.
Also a lot of travel insurance companies require you to be returning to your home country within the period of cover, so make sure you check who will cover you for what before you book anything.
Happy travels! about 6 years ago