Airlines flying to regional airports will now pay £10 less per passenger, Heathrow announced today.
Starting today, departing domestic flight charges will fall more than 30 per cent to £19.13, and if the discount is passed onto travellers, the airport says they'll save over £500m over the next two decades.
The cut is the biggest discount to its charges the airport has made, and fulfils a pledge made by Heathrow in its expansion manifesto to work harder for families across Britain.
It has proposed the discount lasting through to 2037 - as long as it is in the public interest and there's a justification.
Heathrow's chief executive John Holland-Kaye said he was "delighted that we're able to come good" on the promise made earlier in the year "to do more to help Britain's economy grow stronger".
"Putting over £500 million back into the pockets of British families and businesses will help to spur growth in every part of the UK," he added.
From March, Flybe is starting operations from Heathrow for the first time. Last month it announced it will be adding 40 new weekly flights to Edinburgh and Aberdeen to bolster competition and choice for families and businesses.
It will take the slots which become available thanks to the requirement set by the European Commission, following the acquisition of BMI by International Consolidated Airlines Group (IAG).
The airline's executive chairman Simon Laffin said the development is "significantly enhancing our UK domestic route network" and said his firm has "long been lobbying" for the airport to offer more opportunities for domestic flights to boost regional connectivity.