The electronic Oyster travel cards used by millions of London commuters to get around the city are to be made available to overseas visitors as well. An agreement between Transport for London and the VisitBritain tourist board will make the smart card available to tourists before they travel to London. The Oyster cards, which enable passengers to pay for Tube, bus, Docklands Light Railway and tram journeys around London on a pay-as-you-go system, will initially go on sale in India, Hong Kong, Singapore, Spain, Portugal and the USA. By March 2007 the VisitBritain website will also be selling the cards directly to overseas visitors on-line.