In 2019, a client paid a lump sum amount for a "bucket of hours" for work to be performed at a later date. That amount was invoiced to the client, the client remitted a check, and the invoice was closed.

Fast forward to this year, we are creating invoices for the hours worked against this particular project, but I'm not sure how to close these invoices out in QBO. Because the original invoice was paid, there are no funds in a/r that I can match to these new invoices. Is a credit memo the right way to go? A sales receipt? I don't want these invoices to count toward our revenue since they have already been paid for.

Thank you!