The Oyster card is a permanent reusable electronic ticket of credit card size (see image above) which is topped up from time to time by its owner with cash that is used to pay the fares. This was last October. Therefore would appreciate explicit instructions as possible. You can pay cash or credit card. How to Buy a London Oyster Card. The Oyster card is a permanent reusable electronic ticket of credit card size (see image above) which is topped up from time to time by its owner with cash that is used to pay the fares. If you got your Oyster card on or after this date, you can get your £5 refunded once you've used it for one year. Buy paper tickets for Tube and rail journeys from ticket machines. Touch your card on the yellow card reader on the ticket machine, select 'Oyster refund' and follow the on-screen instructions (available in different languages). You need to pay £5 for an Oyster card. Although there are a few manned ticket offices in London, the likelihood is that you will buy an Oyster card from a ticket machine. Find the maximum journey time for your travel so you pay the right fare. If you get a refund from an Oyster card machine at a station, your card will also be canceled, meaning you will lose the £5 activation fee if you have a Visitor Oyster card. You can buy one using either cash or your credit/debit card. Oyster cards are reusable plastic cards that carry credit that can be used for public transportation around London. Just follow the on-screen instructions. You can get up to £20 refunded from your Visitor Oyster card at Tube station ticket machines. You can buy tickets and Oyster cards online and from places across London. Oyster cards aren't accepted at stations between Reading and Iver. Transport for London is making it much faster and easier for passengers to buy and use Oyster, by upgrading ticket machines that will sell Oyster cards directly, with credit loaded. Touch your card on the yellow card reader on the ticket machine, select 'Oyster refund' and follow the on-screen instructions (available in different languages). It sells tickets for both the tube and the Heathrow Express. Keep within maximum journey times . You can also buy them in a few newsagents, which will clearly display a sign in their window. Answer 1 of 226: Am afraid I will be experiencing severe sleep deprivation and therefore no energy to roam the airport to hunt for a Oyster card. There are also ticket machines. Oyster cards are reusable plastic cards that carry credit that can be used for public transportation around London. My travel companion bought an Oyster from the ticket machine at the tube station in Terminal 5. You can buy an Oyster card from a ticket machine in any tube station, various shops which display the oyster logo and lots of other locations.