You have to file an income tax return if your net earnings from self-employment were $400 or more. If your net earnings from self-employment were less than $400, you still have to file an income tax return if you meet any other filing requirement listed in the Form 1040 instructions.

https://www.irs.gov/businesses/small-businesses-self-employed/self-employed-individuals-tax-center

$400 if he is SELF-EMPLOYED. But he claims I have did damage to his business before. What is his business.