Brazilian Account Installment Renegotiation

On a posted invoice or vendor bill, a "Renegotiate Installments" button appears in the form header. It is only shown when the invoice is posted, is a real invoice or bill, and still has at least one unpaid (unreconciled) installment line. Only users with Billing Administrator rights can use it.

Clicking the button opens a wizard that lists the current unpaid installments with their due dates, amounts and payment modes. The user can edit each line directly, or pick a new payment term and a starting date to automatically regenerate all installments from that term. The wizard shows the original total, the new total and the difference; the difference must be zero, otherwise a warning appears and the Apply button stays hidden.

When applying, the module checks that the user is a billing administrator, that the invoice is still posted, that the total is unchanged, that there is at least one installment, that every amount is above zero and that every installment has a due date. It then replaces the unpaid installment lines with the new ones, updates the invoice's payment term if it changed, and posts a message in the invoice's chatter showing the previous and the new installments. The fiscal document (NFe) is not affected.