There is no minimum amount, all income is reportable.
Although it may be news to you that you “have a business” (and most of the other people who get their first 1099-MISC); The IRS considers anything in box 7 of 1099-MISC to be self employment income. Enter the 1099-Misc income, at Other Common income / income from a 1099-MISC . TurboTax (TT) will complete Schedule C or C-EZ for you and allow you to deduct any expenses associated with this income. You'll also have to pay self employment tax (SET)(social security & Medicare) on any "profits" greater than $400.
That's the general answer. But, who is paying him this bonus? Is it his regular employer or is it the appliance manufacturer or vendor? Or somebody else.
If it's his employer, there is a way to cut the self employment tax in half (pay 7.5% instead of 15%) but it's apt to irritate your employer, as the IRS will go after him for the other half.
If the manufacturer paid this, it's known a a SPIFF and is not and subject SET. If this is the case, see https://ttlc.intuit.com/community/taxes/discussion/i-got-a-1099-misc-for-a-spiff-at-my-job-paid-by-t... for instructions.
