The information we are still lacking is whether your son has a W-2 with no tax withheld or if he worked as an independent contractor. You only say he had "no tax withheld." If he has a 1099NEC or if he was paid in cash or by some other means with no Social Security, Medicare or federal and state tax withheld, then he has self-employment income and must pay self-employment tax for Social Security and Medicare and perhaps a small amount of federal and/or state income tax.
Please provide more details about his income and what sort of document he received (if any).
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
