Gross receipts or sales, rents received, other income.

Classify the income and report it on the proper schedule.

But tread carefully.  Some folks know what the magical amount is to max out the earned income credit and maybe didn't really earn the dollars they said they did.

What do you mean?  All of my clients have three kids, income of $15,000-$25,000 and zero business expenses.  Is that a problem?   🤣

Oh, and I check everything on the 8867 but don't actually keep any records.

You must be able to do all of those returns in your sleep 😁