Going anywhere in London this Friday? If you're a Mastercard holder you're in luck - your Tube journey will be free.
In an effort to boost the take-up of contactless payments, the company is offering free travel around the city this Friday - November 14 - and on November 28.
The deal applies to Transport for London buses, the London Underground and overground and DLR routes, and is available for anyone with an NFC-ready Mastercard.
There isn't even any registration process to go through. All customers have to do is use their card to make a contactless payment, and the money will be refunded to their account within 28 days. The deal covers travel between 4.30am on Friday and 1am the next morning; there is, though, a ceiling of £21.80 per day.
The credit card company has launched the Fare Free Fridays initiative as a way of persuading customers to use contactless cards rather than relying on Oyster cards and paper tickets.
Contactless cards don't need to be inserted into a chip-and-pin reader - just waved across the machine. Payments are limited to £20, to limit the chance of fraud.
But while London's transport network was opened up for contactless payments in September, they still account for fewer than 7% of 'pay-as-you-go' journeys.
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A recent report from banking software supplier Compass Plus found that over 70% of consumers still don't have a contactless card - or don't realise that they do. More than a quarter said they didn't know what one was. And of those that have one, fewer than half said they'd used it in the last month.
And a survey from Vista Retail Support this summer revealed that 38% of people avoided one for security reasons. They're right to be concerned: just last week, it was revealed that a flaw in Visa's contactless cards allowed criminals to bypass the £20 limit, potentially allowing them to clear out victims' bank accounts.
That particular bug doesn't appear to have been exploited by criminals. However, many contactless card holders have found that they've been paying for items twice. If the card gets too close to the reader, the money is debited, even when payment's already being made by a different method.
This is a particular danger for users of Oyster cards, with around 1,500 episodes of double-charging a day, and customers have been warned to keep their cards separately.
Read more about contactless cards on AOL Money:
'Flaw' in Visa contactless cards could help criminals steal thousands
Contactless payment for London travellers
Apple's Passbook: a rubbish mobile wallet?