You'll enter this cash income under the Business tab, then Business Income & Expenses, then Profit or Loss from Business, then select the Business Income section. You'll see four choices for the types of business income: 1099-MISC, General Income, Other Income, and Income You Gave Back.
Select "General Income" and you'll see a write-in grid for cash payments. Here you'll write the name of the lawn service in the "description" box, and the amount received.
