Journeys to and from Heathrow Airport will cost more on Crossrail's Elizabeth line than on the London Underground.
Mayor Sadiq Khan and Transport for London (TfL) announced that a premium will apply to single fares to and from the west London hub.
Elizabeth line passengers travelling between zone 1 stations in central London and Heathrow will be charged £12.10 at peak times and £10.10 off-peak.
This is compared with Tube prices of £5.10 at peak times and £3.10 off-peak.
But zone 1-6 travelcards will be permitted and the daily cap for multiple journeys will match the price of Tube and bus travel - currently £12.50.
Elizabeth line journeys elsewhere within TfL zones will cost the same as they do on the Tube.
The new £148 billion east-west railway will enable quicker journeys to Heathrow from many zone 1 destinations.
Travelling from Bond Street to Terminal 5 currently takes around one hour by Tube, whereas the same trip on the Elizabeth line will last just 34 minutes.
Heathrow Express - which runs non-stop services between Paddington and the airport - will continue to set its own fares.
The current Heathrow Connect stopping service between Heathrow Terminals 2/3, Terminal 4 and Paddington will be transferred to TfL from May 20, leading to price reductions on some routes.
Mr Khan said: "I'm delighted to announce today that the cost of travelling on the Elizabeth line in zones 1-6 will be the same price as a similar journey on the Tube - fulfilling a key manifesto pledge to deliver truly world class transport infrastructure which is also accessible and affordable for all Londoners."
The railway is known as Crossrail during construction but will become the Elizabeth line once services begin on three routes from December: Paddington to Abbey Wood, Paddington to Heathrow and Liverpool Street to Shenfield.
The line will fully open in December 2019, with trains running from Reading and Heathrow in the west through 13 miles of new tunnels to Shenfield and Abbey Wood in the east.
Mike Brown, London's transport commissioner, said: "The railway will provide many new direct journey options between Canary Wharf, central London and Heathrow Airport, and will cut journey times dramatically and ensure London remains a world-leading city."