Booking International Flights Need Passport Number
Yes passport number is mandatory to book an international flight tickets.
Booking international flights need passport number. For most countries your passport must be valid for 6 months beyond departure date. You do not need a passport until the moment when you want to board the flight. If you need to get a visa you will need to show the booking when you apply for the visa.
No you do not need a passport to book an international flight. You may be able to book your airline ticket without your passport number. Still when flying internationally you will need your passport eventually.
If the airline requires your passport number check that your passport is valid for travel. Most countries require visitors to present a passport that s valid for a significant period of time such as three or. You will need to include the passport details as soon as they are available and apply for esta in good time if that is applicable.
Perhaps you will need a visa to travel to your destination but you can still make the booking without a passport. However you must have a valid passport in hand before you arrive to the airport. For domestic flights people can carry their photo id proofs within country but if you are planning to travel outside your country than passport is the only valid document to book international flight tickets.
And most do record this information in your booking even if they aren t required to submit it via apis and such. But as long as everything is in order before you fly it s fine to book the tickets now and provide passport details later. Most international airlines will ask for your passport number when you make a reservation for an international flight.