THERE was a time when travelling by rail was all about letting the train take the strain.

But when it comes to battling for compensation for trains that are late, delayed or suddenly grind to a halt halfway through your journey, the level of strain depends on which train operator you happen to be travelling with. Just as buying a ticket can involve negotiating various websites and different journey combinations, there’s sometimes no clear route to gaining compensation for problem journeys.

The level of compensation and what you can claim for, can vary between operators, as can the length of time your service has to be delayed before it even kicks in. Until recently, Virgin Trains was the only operator to offer automatic refunds on certain tickets. It can refund money almost instantly to advance ticket holders if they are delayed more than 30 minutes on certain routes.

Last month, Thameslink and Great Northern announced that smartcard passengers would also receive automatic refunds if held up more than 15 minutes. However they are the exception to the rule.

Most UK train companies – including ScotRail and the Caledonian Sleeper – can take up to 14 days to process a claim once agreed, and that can be a month after the compensation claim was made.

They operate the Delay Repay system, which provides compensation regardless of the reason for the hold up.

The usual threshold is 30 minutes’ delay to your arrival at your destination, which results in a 50 per cent refund of the ticket price. Only four – Gatwick Express, Great Northern, Southern and Thames Link – offer compensation if you arrive 15 minutes late.

By 2020, however, all operators using the Delay Repay scheme are likely to offer compensation after 15 minutes.

It may not seem much, however, according to the National Rail Conditions of Carriage, operators need only pay out for delays of at least an hour, and only then if the delay was their fault.

Season ticket holders face an even more complex journey to receiving compensation. They can claim for “sustained poor performance” when they renew their ticket, assuming they can show a significant number of delays – often around 12 over a 20-day period.

In London, commuters can use a reclaim app, which lets them automatically claim for compensation for delays.