Transport for London (TfL) has introduced contactless payments on the capital's tube and Overground network.
From today, you'll be able to tap in using a contactless payment card rather than an Oyster Card or paper ticket.
The cost will be the same as Oyster's pay-as-you-go fares and both daily and weekly fare caps still apply, meaning you won't miss out if you opt to use a contactless debit or credit card rather than an alternative payment solution.
Shashi Verma, TfL's director of customer experience, said: "Customers can look forward to having an easier and more convenient way to pay for their travel, freeing them of the need to top up Oyster credit and helping them to get on board without delay.
"I would like to remind all of our customers to only touch one card on the reader to avoid paying with a card they did not intend to pay with."
This means if you have more than one contactless-enabled card or an Oystercard, you'll have to keep them separate rather than tapping your whole wallet on the reader.
Contactless payment was introduced on all London buses in December last year and TfL says 69,000 payments are made using contactless on London Buses every day.
Trials on the Underground and Overground network were conducted earlier this year when 5,000 customers were invited to take part.
It's hoped the initiative will help cut down queues at ticket offices and top-up machines in some of the busiest stations around London.
Last week, Apple announced its Apple Pay technology will allow customers in the US to pay for goods in shops using their iPhone. It hasn't been announced when the technology will come to the UK, although rumours suggest we'll be waiting until next year.
