Sohail Qureshi, 53, was allegedly part of a gang who exploited a flaw in the banking system by paying in a worthless company cheques.
He and others allegedly targeted a branch of the bank in St Helens, Lancashire, in a bid to take a total of £20,220,629.
They succeeded in transferring £15m, of which £13.5m was sent to a bank account in Riga, Latvia, destined for Dubai. But the scam was halted after the cash was frozen by the Latvian authorities. The con is said to have taken place between April 1 and July 31, 2004.
Mr Qureshi, of Glasgow, spoke only to confirm his identity when he appeared at Southwark Crown Court. He will return for a plea and case management hearing on December 19. His trial is pencilled in for March 17.