# BR-51

Quoted from a public specification. This page is not a validator, and it is not tax, legal, or accounting advice.

- Country: EU
- Syntax: UBL
- Severity: warning
- Statement language: en
- Last verified: 2026-10-18

## Official statement

> In accordance with card payments security standards an invoice should never include a full card primary account number (BT-87). At the moment PCI Security Standards Council has defined that the first 6 digits and last 4 digits are the maximum number of digits to be shown.

Source: https://docs.peppol.eu/poacc/billing/3.0/rules/ubl-tc434/BR-51/

Peppol BIS Billing 3.0, May 2026 release, EN 16931 model bound to UBL

Severity note: warning, from the Flag column of the Peppol BIS Billing 3.0 UBL rules index retrieved 2026-10-18.

## Plain-language reading

A card primary account number (BT-87) should never be a full number. The message says "should never", not "shall", and it lowercases "an invoice". It names BT-87 and ends with a period. The flag is warning. The context is the card account primary account number. The published test checks that the normalized string length is at most 10. The comparison is <=10 with no space before or after <=. It does not check which digits are present.

## What to change

Keep the card primary account number (BT-87) to at most 10 characters.

## Illustration

Illustration of the condition in the official statement. Not an example published by the source.

**Fails the stated condition.** The card primary account number is longer than 10 characters.

**Passes the stated condition.** That number is at most 10 characters.

## Published context and test

Copied from the source. Not reimplemented on this page.

```
cac:PaymentMeans/cac:CardAccount/cbc:PrimaryAccountNumberID
```

```
string-length(normalize-space(.))<=10
```

[All rule notes](https://einvoicegoblin.com/rules/index.md) · [JSON](https://einvoicegoblin.com/rules/BR-51.json) · [HTML](https://einvoicegoblin.com/rules/BR-51/) · [llms.txt](https://einvoicegoblin.com/llms.txt) · [Invoice page](https://einvoicegoblin.com/) · [Privacy](https://einvoicegoblin.com/privacy.html)