Is it possible to change the date, time, class, or route after the train ticket has been confirmed?

The amendment is allowed as long as 12GO voucher is not yet redeemed for an actual paper ticket at the station.
Only date and time of the departure are possible to be revised. (The route/class CANNOT be amended)

Tags:

Thai Railways

General questions

OK

I don't have a booking number. I have not purchased a ticket yet.