From September, EE customers will be able to use their mobile phone as an Oyster card.
Transport for London will introduce contactless payments for the Tube, DLR, and Overground, so you can pay by tapping your contactless card against a card reader.
EE customers will be the only ones who can pay by touching their phones on the reader, however, thanks to EE's Cash on Tap mobile payments system.
This will mean no more topping up an Oyster card, which should mean fewer queues at ticket machines.
London's buses have had contactless payments for some time now. Earlier this month, they stopped accepting cash as a form of payment.
Cash on Tap has been developed in conjunction with MasterCard. It avoids the issue of card clash – where the gates don't open if you have more than one contactless card in your wallet.
Cash on Tap is free, and is available from Google Play. It will work with more than 500,000 customers' handsets. Daily and weekly caps apply, so you'll pay exactly as much as you would with an Oyster card.
"Users of the world's greatest tube network will shortly benefit from the latest in mobile payment technology, allowing them to use their phone to pay for their daily commute," Gerry McQuade, chief marketing officer at EE, said in a statement.
"As more and more people benefit from the complicity, convenience and security that mobile contactless payments offer, it's rapidly becoming clear that the days of the physical wallet are fast becoming numbered."
Contactless payments will start on the Tube on September 16th.