Credit cards at the turnstile across London by 2013

We don't need no stinkin' Oyster

Transport for London has confirmed that by the end of 2012 it will accept contactless credit and debit cards at the tube turnstiles, just after the Olympic tourists leave.

Those tourists will be able to pay for bus journeys, as London's 8,000 buses will be equipped to accept PayWave, PayPass and ExpressPay before the July kick-off, but upgrading the underground network will take a little longer so Londoners will have to wait until the end of 2012 before being able to cut up their Oyster cards.

Which is what Transport for London wants – Oyster transactions cost the operator money, while dealing directly with the banks is cheaper if more complicated. Buses are relatively easy to bill for: bus journeys in London are billed at a flat rate (£2.20 for cash, £1.30 for prepaid Oyster card, we don't yet know how much for a credit card), while the cost of an underground journey is dependent on the distance travelled.

There's also a time consideration – Transport for London reckons that 500ms is the longest one can wait for a card to be accepted, with 200ms being the target. Contacting a bank and checking the credit available (as required for a debit card) within 200ms is tough, and if the bank happens to be foreign then it is next to impossible. NFC Times reckons that means batching transactions, with rejected cards being blacklisted and caught when the customer leaves the network (London's system requires a tap of the card on exit as well as entry).

Transport for London is also making the usual noises about on-phone transactions, which will come once the phones support NFC and the operators/banks can fund a business model to make it happen. Until then we'll just have to swipe out wallets against the reader and hope it picks out the right piece of plastic – though putting one of them into a keyfob, or a wristwatch or similar, might make more sense.

The plans were leaked to London Tonight back in October, but back then we didn't have London's foppish Mayor Boris Johnson to provide a typically Beano'esque quote: "It is tip-top news that from next year a simple tap of a contactless bank card will be enough to whizz you from A to B in this great city."