Passengers on the Stansted Express can now book online and print their tickets before travelling.
The new e-ticket will also save passengers travelling between Stansted Airport and London Liverpool Street money - £1 off a single and £2 off a return fare.
It will have a barcode for ticket inspectors to scan, verifying the ticket’s validity.
Adrian Warren, Stansted Express’ marketing manager, said: “The new e-ticket service has been well received by both our inbound and outbound audiences in speeding-up their time at the station as they continue with their onward journey.”
The rail operator is also in the process of introducing a fleet of 30 new trains, due to be in service by the end of August 2011.