What it means
Every discount on an invoice line (BG-27) must contain a reason for the discount (BT-139 or BT-140). The reason can be a text, such as "Volume discount" or "Early payment", a code from the UNTDID 5189 list, or both.
Why it matters
Discounts and charges change the amount VAT is calculated on. The recipient needs the amount, the VAT category and the reason to book them correctly and to check that the VAT adds up.
How to fix it
Give every discount a short reason, such as "Volume discount" or "Early payment", or choose a reason code in your invoicing software, and export again.
The rule as published
Each Invoice line allowance (BG-27) shall have an Invoice line allowance reason (BT-139) or an Invoice line allowance reason code (BT-140). Business terms: BG-27, BT-139, BT-140
Where this rule applies
| Rule set | Version |
|---|---|
| EN 16931 (UBL) | 1.3.17 |
| EN 16931 (UBL credit note) | 1.3.17 |
| EN 16931 (CII) | 1.3.17 |
| XRechnung 3.0 (UBL) | 3.0.2 |
| XRechnung 3.0 (UBL credit note) | 3.0.2 |
| XRechnung 3.0 (CII) | 3.0.2 |
| Peppol BIS Billing 3.0 (invoice) | 2026.5 |
| Peppol BIS Billing 3.0 (credit note) | 2026.5 |
| Factur-X 1.09 BASIC | 1.0.9-2 |
| Factur-X 1.09 EN 16931 | 1.0.9-2 |
| Factur-X 1.09 EXTENDED | 1.0.9-2 |
| ZUGFeRD 2.5 BASIC | 2.5.2 |
| ZUGFeRD 2.5 EN 16931 | 2.5.2 |
| ZUGFeRD 2.5 EXTENDED | 2.5.2 |
| SI-UBL 2.0 / NLCIUS (invoice) | 2.0.3.13 |
| SI-UBL 2.0 / NLCIUS (credit note) | 2.0.3.13 |
| NLCIUS (CII) | 1.0.3.13 |
| France CTC (UBL invoice) | 1.4.0-04 |
| France CTC (UBL credit note) | 1.4.0-04 |
| France CTC (CII) | 1.4.0-04 |
| CIUS-RO UBL Invoice 1.0.9 | 1.0.9 |
| CIUS-RO UBL Credit Note 1.0.9 | 1.0.9 |
Check your file
Drop your e-invoice to see whether BR-42 still fails, and which other rules do.