Account Payment Promissory Note

This module adds promissory note handling to customer payments in Odoo's Invoicing app.

On a payment form you get a new "Promissory Note" checkbox and a "Due Date" field. The due date only appears once the checkbox is ticked. When you tick it, Odoo tries to fill the due date automatically with the latest due date found on the invoices being paid, but only when those invoices all belong to the same customer. If you untick the checkbox, the due date is cleared.

The same checkbox and due date are available in the "Register Payment" wizard, so you can flag a promissory note while recording a payment from an invoice. There, if you leave the due date empty, each created payment takes the latest due date of the invoices it settles; if you fill it in, that date is used for all payments created.

When a payment is saved, the due date is copied onto the accounting entry lines as their maturity date, so the accounting reflects when the promissory note is expected to be paid. If the promissory note flag is removed, the maturity date falls back to the payment date.

A "Promissory Note" filter is added to the payments search view, letting you list only payments flagged as promissory notes. The due date on a saved payment can no longer be edited once the payment is no longer in draft.