If more than $400 of self-employed income then they must file a tax return and pay the SE tax on any amount over $400.
The most you can contribute to all of your traditional and Roth IRAs is the smaller of:
For 2019, $6,000, or $7,000 if you’re age 50 or older by the end of the year; or
your taxable compensation for the year.
(Taxable compensation is generally wages that you worked for - W-2 or net self-employed income minus the deducible part of the SE tax, but can include commissions, certain alimony and separate maintenance, and nontaxable combat pay ).
See IRS Pub 590A "What is compensation" for details:
https://www.irs.gov/publications/p590a#en_US_2018_publink1000230355
See this IRS article for Roth contribution limits:
https://www.irs.gov/retirement-plans/roth-iras
**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.**
