CII-SR-487: The amount due may appear only once

What it means

The totals section (SpecifiedTradeSettlementHeaderMonetarySummation) holds the amount due for payment (BT-115) in the element DuePayableAmount. The check counts how often it appears and allows at most one.

Why it matters

This is the amount the buyer is asked to pay and the figure the payment is matched against. With two values the recipient cannot tell what to pay. This is a fatal error and the invoice is rejected.

How to fix it

Invoicing software normally calculates the amount due itself, so a repeat usually points to an export fault or a hand edit. Create and export the invoice again. If you edit the XML yourself, delete the extra DuePayableAmount and keep the one that equals the total including VAT, minus what is already paid, plus any rounding amount.

The rule as published

DuePayableAmount shall occur at most once in SpecifiedTradeSettlementHeaderMonetarySummation.

Where this rule applies