Children will be able to travel free on the Heathrow Express in time for the Easter holidays.
The airport rail service will enable children under 16 accompanied by a parent or guardian to travel free of charge from March 27.
The move follows a ‘Kids go free’ offer run in the past for limited periods of time.
The initiative is part of a plan by the company to increase the number of leisure travellers using the 15-minute service.
Heathrow Express is also cutting single standard tickets over the Easer weekend, Good Friday April 3 to Bank Holiday Monday April 6, from £21.50 to £10 and return tickets, valid for travel after the four-day period, from £35 to £31.50.
Director Fraser Brown said: “As many parents know only too well, some travel organisations tend to charge families with children more, not less, in the school holidays. We are doing the opposite.
“Two thirds of the people who use our service are travelling on business. We want to encourage more leisure passengers, families in particular, to use our service. Allowing children to travel free at all times from now on is a key part of doing this.
“As well as making things easier for hard-working families heading abroad for a break, we also want to welcome more families visiting Britain from overseas.”
Gordon Innes, chief executive of London & Partners, the official promotional organisation for the capital, said: “London is the most visited city in the world and plays hosts to millions of families each year. It’s great news that Heathrow Express are making visiting the capital even more affordable for families travelling with children.”