Barclays Bank is spending pounds 750,000 placing at least 20 machines in Underground stations over the next two years. It already has a cash machine at the entrance to the Channel tunnel.
Barclays machines at Oxford Circus and Bond Street stations will start operating this month. Its machines can also be used by Lloyds, Bank of Scotland and Royal Bank of Scotland customers.
Midland Bank is planning to put machines in Tube stations and hopes they will be operational at Liverpool Street and Piccadilly Circus in October, although planning permission from English Heritage will be needed for the latter site because it is a listed building.
Building societies may also start installing machines underground. Nationwide has 27 stand-alone machines, and is keen to develop more sites.