Rail passengers will now be able to claim compensation when trains are more than 15 minutes late, the Department for Transport has revealed.
The policy, Delay Repay 15, will be launched first on Southern trains, which have suffered months of disruption over disputes about the role of conductors.
It will then be rolled-out to Govia Thameslink Railway (GTR) services in the coming months before extending across the country.
Existing compensation rules mean passengers can only claim pay outs when services are delayed by at least 30 minutes, but one railway regulator estimates just one in five people actually do so.
Only three in four GTR trains arrived on time between August 21 and September 17 this year with almost one in 10 cancelled or arriving more than 30 minutes late, Network Rail figures show.
Under the new scheme, passengers will be able to claim 25 per cent of a single fare on trains delayed between 15 and 29 minutes and 50 per cent of a single fare on train delayed between 30 and 59 minutes.
Customers will be granted a full refund on single fares on train delayed between one hours and one hour 59 minutes and a full refund of their total ticket cost of their service if more than two-hours late.
A DfT spokeswoman could not give a start date for the scheme but said it would apply to Southern services "soon".
Transport Secretary Chris Grayling said: "We recognise that, above all else, passengers want a reliable train service, but when things do go wrong it is vital that they are compensated fairly.
"Together with the Consumer Rights Act, this policy shows we are putting passengers first and making sure they receive due compensation for poor service."
Following its introduction on GTR, the scheme will be launched across the network, starting with the new South Western, West Midlands and Southeastern franchises.
GTR runs four services: Southern, Thameslink, Great Northern and Gatwick Express.
All future DfT rail franchises will include a requirement to introduce the policy.
Officials said they would explore opportunities to roll it out for all DfT franchises during this Parliament.
Charles Horton, Govia Thameslink Railway CEO, said: "We warmly welcome this announcement.
"When passengers are delayed, they deserve compensation and we strongly advise all our passengers to make a claim.
"This announcement will be good news for those with shorter journeys who think it is unfair they receive nothing for delays under 30 minutes.
"Now a decision has been made, we will work hard to implement this as quickly as possible."
