The Canada Revenue Agency confirms that a judge will continue a case against Peter McCallion, 60.
He is best remembered for his failed business dealings which led to a conflict of interest hearing against his mother in 2010.
The conflict case against the mayor was dismissed in June after a Superior Court justice ruled the mayor's conflict was minor and didn't warrant ousting her from office.
Her son, a real estate agent, now faces allegations that he has not filed corporate or personal income tax returns since 2004.
If found guilty, which could be determined as early as February, he could face a maximum fine of $25,000 and 12 months in jail on each count.
McCallion, 92, known as "Hurricane Hazel" for her fiery personality, has been Mississauga's mayor since 1978.