# KoSIT XRechnung errors: four rules to check first

- Date: 2026-04-29
- Modified: 2026-08-29
- Reviewed: August 29, 2026
- Reading time: 2 min read

Understand common KoSIT XRechnung errors, the exact BR-DE rule, the affected invoice field, and the next useful check.

> Reviewed against KoSIT validator configuration, Peppol BIS validation rules.

A KoSIT report tells you which validation rule failed and where it failed. Start with the rule ID, then correct the named Business Term (BT) or Business Group (BG). Do not guess from the short error text.

Use the validator configuration that matches the XRechnung version in the file. The KoSIT 2026-01-31 release includes XRechnung 3.0.2; it is not a general validator for every historical version.

## What KoSIT checks

The XRechnung configuration validates UBL or CII XML against the XML schema, EN 16931 rules, and German XRechnung rules. It does not validate the PDF/A-3 container of a ZUGFeRD or Factur-X file. Use a hybrid-invoice validator for that separate task.

For an XRechnung 3.0.2 document, BT-24 should identify the profile as `urn:cen.eu:en16931:2017#compliant#urn:xeinkauf.de:kosit:xrechnung_3.0`. Keep the exact value from the selected specification; a shortened or mixed ZUGFeRD identifier selects the wrong rule context.

## Four common BR-DE failures

**BR-DE-1 — Payment instructions:** the invoice must contain PAYMENT INSTRUCTIONS (BG-16). Check the payment means and the related account or direct-debit data.

**BR-DE-2 — Seller contact:** the invoice must contain SELLER CONTACT (BG-6). BR-DE-5, BR-DE-6, and BR-DE-7 then require BT-41, BT-42, and BT-43.

**BR-DE-15 — Buyer reference:** Buyer reference (BT-10) is missing. For a German public recipient, use the routing value that the recipient supplied, often a Leitweg-ID. Do not invent one.

**BR-DE-16 — Seller tax identifier:** when the listed VAT category codes are used, provide at least one of Seller VAT identifier (BT-31), Seller tax registration identifier (BT-32), or Seller tax representative VAT identifier (BT-63).

## A safe correction sequence

- Confirm the XRechnung version and the validator release.
- Open the first fatal rule in the report and note its XML location.
- Correct the named BT or BG in the source data, not only in the generated XML.
- Generate the invoice again and rerun the same validator.
- Review warnings separately. A warning is not the same as a rejected invoice.

## FAQ

### Does KoSIT validate ZUGFeRD PDF/A-3?

No. The XRechnung configuration validates UBL or CII XML. A ZUGFeRD or Factur-X file also needs checks for the PDF/A-3 container, embedded XML, metadata, and semantic agreement between PDF and XML.

## Official references

- [KoSIT validator configuration](https://github.com/itplr-kosit/validator-configuration-xrechnung)
- [Peppol BIS validation rules](https://docs.peppol.eu/poacc/billing/3.0/rules/)