https://www.nolo.com/legal-encyclopedia/when-does-your-child-have-file-tax-return.html
$400 if self-employed
I do not agree with this answer given the answer found in: <a rel="nofollow" target="_blank" href="https://www.nolo.com/legal-encyclopedia/when-does-your-child-have-file-tax-return.html">https://www.nolo.com/legal-encyclopedia/when-does-your-child-have-file-tax-return.html</a>
filing requirement is still $400 if the income comes from self employment ... that didn't change.