In late 1988 it was amicably agreed at a partners meeting at Trevor Jones & Co. Chartered Accountants (Waltham Cross) that Thomas Mines and David Brown should leave that practice, taking with them their own clients and staff.

Tommy and Dave decided that their Christian names would combine to form the trading name. They deemed it fitting as Thomas David would pride itself on personal relations with its clients. The first offices of Thomas David were in High Street, Hoddesdon, Herts, but in 1991 the firm expanded to incorporate two offices. Dave operated in Ware (Mill Studios) while in Hertford (Mercer House), Tommy was joined as partner by Michael Palmer.

Dave moved on to offices in Goffs Oak (Tudor Lodge) from Ware and then rejoined the remainder of the team in Hertford after Tommy’s semi-retirement in 2001. Dave was now senior partner at Mercer House and has since moved the team to Castle Gate (April 2005).

On 1 October 2008, Michael Palmer left the practice, leaving Dave Brown, Huw Davies and Mandy Brown to be the active partners at Castle Gate. Ex-senior partner Tommy Mines continues to trade from Bengeo.