Train passengers should be able to use their Oyster cards on most of the London rail network by the end of 2009. Currently the Oyster card can be used on London Overground, the London underground, buses, trams and the Docklands Light Railway. However, many suburban rail firms do not yet accept the pay as you go card. The London Mayor Boris Johnson has said that an agreement with most rail companies is near. The one exception appears to be South West Trains which currently has no plans to allow customers to use the Oyster card on its service.