Rail passengers can buy and scan tickets with their smartphones under a new system rolled out by Chiltern Railways.
The train company is the first in the country to launch the App and Go system.
Passengers can pay for travel on their mobiles and then touch their phones on gates.
The Chiltern Railways commuter area of Oxfordshire and Buckinghamshire is covered by the new scheme.
The service is designed for passengers who do not travel frequently enough for a season ticket but do not wish to queue at a ticket office every day.
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