David Douglass, 45, from Silver Birch Drive, Hollywood, had been charged with cheating the public revenue contrary to common law.
HMRC argued Douglass had evaded tax estimated at £730,000.
He entered a guilty plea on 11 February and sentencing is due to take place on 19 April.
Douglass worked for Honister Partners, formally Bates, between March 2006 and July last year. He previously worked for Berry Birch & Noble Financial Planning.