Error code BR-27 means: the net price of an item on an invoice line is negative. That is never allowed.
What does BR-27 mean?
The validator shows this message (as worded in the official rules):
[BR-27]-The Item net price (BT-146) shall NOT be negative.The item net price (BT-146, Price/PriceAmount) must not be negative. To create a negative line, use a negative quantity and a positive price, or an allowance. For a full refund, use a credit note.
Common causes
- A discount, return or advance payment was entered as a line with a negative price.
- A credit note was created as a regular invoice with negative prices.
- A conversion from another system put the minus sign on the price instead of the quantity.
How to fix it as the sender
- Put the minus sign on the quantity and keep the price positive: −3 × 100.00 = −300.00.
- Process a discount as an allowance on the line or on the invoice, with a positive amount.
- To reverse an entire invoice, issue a credit note (type 381) with positive amounts.
Received an invoice with this error?
Ask the supplier to correct the invoice, or for a credit note if it is a refund.
Example in the XML
❌ Wrong
<cbc:InvoicedQuantity unitCode="HUR">-3</cbc:InvoicedQuantity>
...
<cac:Price>
<cbc:PriceAmount currencyID="EUR">-100.00</cbc:PriceAmount>
</cac:Price>✅ Correct
<!-- negative quantity, positive price -->
<cbc:InvoicedQuantity unitCode="HUR">-3</cbc:InvoicedQuantity>
<cbc:LineExtensionAmount currencyID="EUR">-300.00</cbc:LineExtensionAmount>
...
<cac:Price>
<cbc:PriceAmount currencyID="EUR">100.00</cbc:PriceAmount>
</cac:Price>Both snippets come from a complete test invoice that we checked with our validator: the wrong version gives exactly this message, the correct version no errors at all.
Good to know
An advance payment is not deducted with a negative line in Peppol, but with the prepaid amount (PrepaidAmount) in the totals.
Check your invoice
Drop your XML into the free validator. You see right away whether this error still occurs, with a link to the explanation for every message.
Official rule
The full rule with its technical test (Schematron) is in the official Peppol documentation:
Related error codes
- PEPPOL-EN16931-R120: The net amount of an invoice line does not equal quantity × unit price, plus charges and minus allowances on that line.
- BR-CO-15: The total with VAT is not equal to the total without VAT plus the VAT amount.
Frequently asked questions about BR-27
How do I add a discount to a Peppol invoice?
As an allowance (AllowanceCharge with ChargeIndicator false) on the line or invoice, with a positive amount. Or as a line with negative quantity and positive price.
When should I use a credit note?
When you reverse an invoice fully or partly. A credit note (type 381) has positive amounts.