In an increasingly cashless world, where more and more people are paying by waving cards or tapping their phones, street performers in many cities have seen the coins and bills in their tip boxes tail off. London thinks it's on to a solution.
The Mayor of London's Busk in London initiative has partnered with Swedish firm iZettle to distribute contactless readers to buskers around the city who have registered with the mayor's office. Enjoying the music? Step over to the reader with your card or phone, and make a donation.
One busker, Charlotte Campbell, who's been part of the initial trial, told BBC she's happy with it: "More people than ever tap-to-donate whilst I sing, and often when one person does another follows." Of course, unlike cash, those takings are on record for the tax man.
IZettle sees a market for its readers for charities and small businesses, and they're not alone in thinking they're on to a good thing: PayPal has just announced it's buying the company for $2.2 billion.