It is not "per job." If you earn at least $400 total as an independent contractor the tax law is that you have to report the income as self-employment income.
https://ttlc.intuit.com/questions/2903027-how-do-i-report-income-from-self-employment
What if I didn’t get a 1099-MISC, but made money from self-employment?
If you weren’t paid $600 or more, a business isn’t required to send you a 1099-MISC, but you still need to report the income.
To enter your self-employment income not reported on a 1099-MISC:
- When in your account, select the Take Me to My Return button on the main screen.
- Type “Schedule C” in the Search box
- Select the “Jump to” link.
- Answer the general questions about your business (or select Edit at the work summary screen).
- At the Let’s get income for… screen, select Additional Income.
If you did make $600 or more, contact the company or individual you worked for.
https://ttlc.intuit.com/questions/2926899-how-does-my-side-job-affect-my-taxes
https://ttlc.intuit.com/community/self-employed/help/what-is-the-self-employment-tax/00/25922
https://ttlc.intuit.com/questions/2902389-why-am-i-paying-self-employment-tax
**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.**
