For up to six months, Network Rail will only confirm train timetables six weeks in advance meaning some passengers who book journeys 12 weeks out might be eligible for refunds.
But passengers are being told to book as normal and if their journey is changed or cancelled later on, they should be able to claim their money back if they decide not to travel.
And if a fare gets cheaper – usually around the six-week mark – passengers can book the cheaper fare and request a fee-free refund on their original ticket
Network Rail, which is responsible for publishing the national railway timetable, said the vast majority of passengers will be unaffected because 98% use season tickets, walk-on fares or book less than six weeks before travel.
But it did admit that some passengers will be affected.
The temporary changes are because of unexpected alterations to infrastructure projects and the introduction of new trains and new services by some operators.
There was then a significant delay to the major electrification work between Manchester and Preston, said the industry body, the Rail Delivery Group.
Rail companies must minimise disruption
Which? managing director of public markets, Alex Hayman, said the change will make it more difficult for rail passengers to plan their journeys.
‘So it’s vital that rail companies do everything possible to make sure passengers are given clear and up-to-date information as soon as possible.
‘Anyone with a ticket for a journey that is disrupted or cancelled should claim a refund or compensation.’
Rail companies sorry for the inconvenience
Managing director of customer experience at the Rail Delivery Group, Jacqueline Starr, said for the vast majority customers this change will have little or no effect.
But the reduced time to plan and book certain journeys may inconvenience some people and for that we apologise.
‘Train operators are working together doing all they can to minimise the impact of this change on customers. That’s why, if people have booked on a train that is cancelled, delayed or where their reservation will not be honoured, and they decide not to travel, they will be given a full refund.
‘Should tickets go on sale at shorter notice than usual, people will still be able to get the same range of discounted fares as normal.’
The core train timetable changes twice a year and the May 2018 timetable change is the largest in living memory, needing the rescheduling of almost four million services – some 600% more than normal.
Claim for compensation if your train is delayed or cancelled
If your train was delayed for least 15 minutes or 30 minutes (depending on your train company), you’ll be entitled to a full or partial refund for that journey.
Most UK train companies now offer compensation under the national Delay Repay scheme.
You can also cancel your ticket and get a refund if your train is delayed or cancelled.