How do I reverse a receivable?

Receivables can be reversed either by application or, in the case of invoices, by voiding. For example, let's say a customer has an open receivables balance of $4500. When that customer sends you a check for $4500, you can apply that cash to the invoice, thus reversing the open balance down to $0. Similarly, credit memos can be applied to invoices (or debit memos) to reduce or reverse a receivable amount. For invoices, you also have the option to void them, which reverses them back to an unposted state.