It also depends on the nature of the work, for example if the child is doing what would normally be called "household chores" that are expected to be done by household members, then the IRS could look at it as sham employment for you to claim a child's allowance as a deductible business expense.
**Disclaimer: This post is for discussion purposes only and is NOT tax advice. The author takes no responsibility for the accuracy of any information in this post.**
