Sometimes a client invoice is marked as overdue, but the client claims to have paid the bill and may even have submitted proof of payment.
Often, the explanation is that the client has generally been behind on paying their invoices, resulting in several unpaid invoices piling up, and that the payment in question actually covered an earlier invoice that had been outstanding for some time.
This can usually be verified by opening the client’s payment window and checking the invoice dates to see if any invoices have a parenthesis indicating a later payment date.
In the example below, the client claims to have paid the invoice sent on October 19, but in reality, they spent the invoice from September and still owe payment for the most recent one.
