The 66-year-old, of Hackballscross in north County Louth, denies nine charges of failing to supply proper tax returns between 1996 and 2004.
The trial is expected to last up to three weeks.
If he is found guilty he could face up to five years in jail.
The trial is taking place before three judges in a non-jury court.
The prosecution has begun its opening statement in the trial of the prominent republican Thomas Slab Murphy at the Special Criminal Court in Dublin.