A temporary train ticket sale claiming to be the biggest nationwide offer of heavily discounted fares has begun.

As the government and rail industry seek to boost demand after the slump caused by the pandemic, more than one million tickets are on offer in the “Great British Rail Sale”. But most fare types are not included. So what are the offers to look out for?

These are the key questions and answers.

What’s the deal?

Deeply discounted travel on a range of rail journeys from 25 April to 27 May inclusive. Most tickets will be half price.

Almost all of the available tickets are Advance fares. These require committing ahead to a specific train.

Just like airline tickets, the price varies depending on demand: between Edinburgh and London on LNER, for example, normal Advance tickets for Tuesday 3 May range from £27.80 to £72.50. But from information put out by the Department for Transport (DfT) it appears that the discount will apply to specific Advance fares, rather than all of them.

On LNER, £22 one-way Edinburgh-London tickets are available on some trains. The flat rail sale fare between London and Leeds is £15.

The following discounted prices have been quoted by the DfT:

GWR appears to be selling all Cardiff-London Paddington tickets, including peaks, for £25 one-way, with Bristol to/from London at a flat £18.

Avanti West Coast, which runs trains from London Euston to the West Midlands via northwest England and Scotland, has badged discount tickets with a red “rail sale” symbol. One-way fares to and from the capital are Glasgow £26, Manchester £23, Liverpool £17 and Birmingham £8.

Is the discount available for any journey?

Absolutely not. The DfT says: “Great British Rail Sale tickets are not available on all routes, are limited and subject to availability and exclusions.”

Most tickets do not qualify, including Anytime, Off-peak (except in a few cases), Seasons and Flexi-Seasons.

On any date?

Not necessarily. The 25 April-27 May window for travel includes the long weekend of 30 April to 2 May - when London Euston station and the southern end of the West Coast main line will be closed.

More widely, is likely that high-demand times of day will be excluded from the deal.

Can I make a connecting journey?

Connections should be possible when booking direct on the same operator. The DfT cites a Portsmouth-Penzance ticket for a discounted fare of £22, which is available for travel on GWR via Westbury.

But connecting journeys on different train operators do not qualify. For example, normally you can book an Advance ticket from Birmingham to Barrow in Furness using Avanti West Coast as far as Lancaster and a Northern train from there.

With the deal, you would have to book two journeys to save money. The Trainsplit organisation says: “If your journey involves different train companies you’ll get a ‘No Discounts found’ message.” The website combines fares to find the cheapest deal.

For example, between London and Hebden Bridge in West Yorkshire on 16 May it prescribes a first-class LNER ticket from King's Cross to Doncaster then two separate Northern tickets via Leeds. The fare is £35 but Trainsplit adds a £2.48 fee.

Do railcard discounts apply?

Yes, which will reduce these fares by a further 34 per cent. Between Birmingham and London, for example, the £8 ticket will be cut to £5.30.

Can I book in first class?

Yes, at least on LNER. London to Newcastle is £19.80 in standard and £42.20 in first; an uplift of 110% appears to be the average.In addition, individual train operators may have upgrade offers that can be used in connection with a discounted ticket.

How do I book?

The DfT says: “Customers should visit nationalrail.co.uk/railsale to see what discounts are available for the location they wish to visit.”

Then book through one of these channels:

People with access issues are able to seek help at the ticket office of a staffed railway station.

How quick should I buy?

As soon as you can. One million tickets may sound like a large number, but compared with the usual numbers of rail journeys in a 33-day spell (more than 160 million) it is tiny. Many trains will sell out of cheap tickets very quickly.

The Rail Delivery Group, which is coordinating the offer with the DfT and train operators, says: “The number of Rail Sale tickets offered by each participating Train Company will vary and are limited in number so we’re encouraging people to act quickly because when they’re gone, they’re gone.”

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