I do not know of any check boxes after the fact. You could do an invoice adjustment and change it that way. The invoice will still LOOK like it's a 1099, but when that invoice is paid, the amount will not go into the 1099 bucket. I had to test this. Not sure I'd recommend it because the invoice will look one way, but act another. I think the best thing is to back out that invoice and then reinter it with slightly different invoice number. When clients say this to me, I usually ask them to show me how it was done in the ""old"" system. Our memories don't always remember things correctly, or perhaps they were doing something different and it came out as ""I changed a checkbox.