Transport for London (TfL) has teamed up with O2 and Nokia to trial a mobile handset that incorporates the Oyster smartcard ticketing technology.
Around 500 customers will trial 'O2 wallet' phones which will enable them to use their mobile handset to pay for travel and enter the transport system across London.
More than 10 million Oyster cards have been issued and just 3% of payments on London's underground and buses are now made using cash.
The O2 wallet trial will determine how customers feel about having Oyster technology embedded in their phone.
TfL will use the trial to consider offering passengers an alternative to the regular Oyster card.
Each triallist will be given a Nokia 6131 handset installed with the O2 Wallet.