I suspect you
received a Form 1099-MISC with the amount paid you in Block 7. That means the
issuer, either correctly or incorrectly, assumed it was self-employment income.
They aren't always right.
TurboTax asks
several questions to determine if this is self-employment income, or whether it
is casual income not subject to self-employment tax. If, based on the answers,
it is most likely not self-employment income it is not treated as such on your
return.
Unfortunately,
the IRS takes a "shoot first and ask questions later" position on
whether it is self-employment income by making the assumption that the issuer's
Form 1099-MISC is correct, not your tax return. That doesn't mean they are
correct.
When you receive this
type notice, all you can do is reply to the IRS explaining that it is one-time
or casual income or receipts not subject to self-employment tax. See https://ttlc.intuit.com/questions/1899537
