How to get archived accounts receivable in status Unknown in the in-progress receivables list – Billtobox

Please note that the following content describes a workaround as no functionality exists nor is currently foreseen to achieve the desired result.

In the outbound archive, click on an invoice to view the details page.
In the Amount Paid field, enter a small amount (eg € 0.01) and a payment date then save these changes.
The invoice will now appear in the archive as Partially paid, and will also be shown in the in-progress list of the Accounts Receivable menu, with a due date as status.
You can reset the amount paid to 0.00, if desired. The invoice will remain in the in-progress receivables.