Account force early payment discount

Normally Odoo only grants the early payment discount if you pay before the discount date set in the payment terms. This module adds a way to override that rule.

On a customer invoice or vendor bill (account.move), a new checkbox "Force early payment discount" appears next to the payment terms. It is only shown when the payment term actually offers an early discount and, once the invoice is posted, when a discount date and amount exist. If you tick it, the discount will be granted even if you pay late.

When you register a payment, the payment wizard (account.payment.register) shows a checkbox "Apply Early Payment Discount Past Date" whenever at least one selected invoice has a discount date already in the past. Ticking it forces the discount for all selected invoices, regardless of their individual flags. Invoices that already carry the flag are forced automatically, even if you do not tick the wizard checkbox.

The module recalculates the amounts to pay and the payment values so the forced discount is included, and it only applies to invoices that are eligible: same currency, an early-discount payment term, and no payment already matched against the payment term lines.