Haigh moved to London in 1936, and became chauffeur to William McSwan, a wealthy owner of amusement arcades. He also maintained McSwan's amusement machines. Thereafter he pretended to be a solicitor named William Cato Adamson with offices in Chancery Lane, London; Guildford, Surrey; and Hastings, Sussex. He sold fraudulent stock shares, purportedly from the estates of his deceased clients, at below-market rates. His scam was uncovered by someone who noticed he had misspelled Guildford as "Guilford" on his letterhead, an unlikely mistake from an educated solicitor. Haigh received a four-year prison sentence for fraud. Haigh was released just after the start of the Second World War; he continued as a fraudster and was sentenced to several further terms of imprisonment.