You’ll need to have some form of identification on both domestic and international flights. All customers on international flights must have a valid passport and, where required, a valid visa.
In most countries around the world, the passport must have at least six months validity from the date of the return flight.
The immigration authorities of certain countries may deny entry into their territory if the passport's validity does not meet these conditions. The airline may also refuse boarding if your passport does not meet the requirements or if you do not have the necessary entry visa.
Please be sure to check the latest entry regulations as well as other information about the destination on the website of the respective foreign ministry.