Travellers in the catchment areas of Cardiff, Bristol and Exeter airports are being targeted by British Airways in a rail-air ticket tie-up.
Fares will be available to book via agents for travel from 11 First Great Western stations to Heathrow via Paddington and the Heathrow Express.
A single booking will combine air and rail travel from Friday (December 5) through a new partnership between BA, First Great Western and Heathrow Express.
If a train is delayed or a connection missed, passengers will be rebooked on the next available flight and get overnight accommodation if the next service is not until the following day.
Travellers will also be able to take the next available train if their flight is delayed.
The deal will be available from First Great Western stations at Oxford, Bristol Parkway, Bristol Temple Meads, Bath, Cardiff, Exeter, Plymouth, Swansea, Penzance, Par and St Austell.
BA head of UK and Ireland sales and marketing, Stephen Humphreys, said: “This is a great new way for our customers living in Wales and the West Country to get on track right from the start to enjoy a trip with British Airways.
“Our partnership with First Great Western and Heathrow Express will make flying more accessible and convenient for customers travelling from regions in the UK without local airports.”
Mark Hopwood, managing director of First Great Western, said: “This is all part of our work to make journeys easier and simpler for our passengers. For many of our customers travelling to Heathrow by train already saves time, hassle and money.
“Complemented by our work to add more seats to trains, the upgrade of our first class accommodation and free Wi-Fi, this product will make it even more attractive BA customers looking for a worry-free way to get to Heathrow.”
Heathrow Express managing director, Keith Greenfield, said: “This partnership removes a layer of hassle for customers and affords them extra protection against possible problems. This kind of joined-up travel is what today’s leisure and business travellers expect.”