Mobile phones: the new credit cards? However, we are on the verge of major changes, says Dave Birch at Consult Hyperion. I already check in and fly with BA using my phone. On Monday, I bought lunch using my Starbucks app. One key phone technology for a future "digital wallet" is Near Field Communication, or NFC. It makes your phone work like a contactless credit card. You wave the handset over a reader and the inbuilt radio registers a payment, or opens a transport turnstile or hotel room. The latest NFC technologies work even when you don't have a 3G signal or your handset is switched off. New Samsung, HTC and Nokia models incorporate NFC, but not (so far) the iPhone. In July, Mastercard and mobile network EE launched Cash on Tap (explore.ee.co.uk/cashontap), which allows EE 4G customers to pay with one tap of an NFC-enabled phone. Phone-compatible contactless payments are currently accepted in over 1 million locations spread across more than 50 countries, though Cash on Tap does not currently work in the USA. Weve (weve.com), a joint venture between EE, O2 and Vodafone, takes things a step further, combining payment from several credit and debit card accounts with offers and coupons stored in the same digital wallet. The loyalty service launches in the first half of 2014, with NFC-powered mobile payments coming later next year. Visa's digital wallet service V.me (uk.v.me) launches later this year. The security arrangements for lost or stolen cards are the same as for credit or debit cards. So, how long before I can board a bus outside my house, switch to a train, alight in Paris, buy lunch at a brasserie, book a hotel, take a cab and then pay for a guided tour without once using cash or credit card? "This is still some way away, perhaps three to five years," says Dave Birch. But it is an appealing vision. Ask the experts Our Q&A service allows you can pick the brains of our experts at home and abroad. Email your query to asktheexperts@telegraph.co.uk. We won't be able to answer them all, but we will do our best. About Donald Strachan Donald is a specialist in technology and new media. Click here to find out about our other experts