Where I come from, if they went back and looked at the years you were only earning what would normally be employment income from the single employer, they would classify it a "personal services corporation" and move any income in the company you declared as corporate income into your personal hands, tax you at personal rates and make you pay interest on that difference for the time you had it misclassified.
Your jurisdiction might not do that, but I'd be damn careful and if you are liable that way, they might let you off the hook on the interest if you went back and declared it correctly before they do.
Your jurisdiction might not do that, but I'd be damn careful and if you are liable that way, they might let you off the hook on the interest if you went back and declared it correctly before they do.