Nothing. CRA would first charge interest and if you didn’t comply, then come and garnish your wages. Only two things certain in life are death and taxes. Most Millionaires and billionaires don’t earn money through taxable income. They are not employed or filing a T4 every year. They usually earn through capital. Which they may not sell until they need. Hard to tax this without screwing over small businesses and those who take risks to be employers. //noted as someone in top tax bracket