KoSIT-validated

XRechnung Validator
B2G Compliance Check

Validate your invoices against KoSIT Schematron rules before submitting to ZRE, OZG-RE or state portals.

Try the Validator API Docs

What KoSIT Validates

The KoSIT (Koordinierungsstelle für IT-Standards) publishes the official Schematron rules for XRechnung. Every invoice submitted to a German public authority must pass these checks.

Our validator runs the full XRechnung 3.0.2 rule set: UBL 2.1 schema validation, EN 16931 business rules (CEN), and the German CIUS extension rules published by KoSIT.

UBL Schema EN 16931 Rules KoSIT CIUS
Validation Layers
1

UBL 2.1 Schema

XML structure and data types

2

EN 16931 (CEN)

European business rules (BR-*)

3

XRechnung CIUS

German B2G rules (BR-DE-*)

Validate via API

Send JSON, get validation results. No PDF generated.

POST /v1/validate XRechnung 3.0.2 
curl -X POST https://api.thelawin.dev/v1/validate \
  -H "Authorization: Bearer tlw_sandbox_..." \
  -H "Content-Type: application/json" \
  -d '{
  "format": "xrechnung",
  "invoice": {
    "number": "RE-2026-042",
    "buyer_reference": "04011000-1234512345-06",
    "seller": { "name": "Acme GmbH", "country": "DE" },
    "items": [{ "description": "Consulting", "quantity": 10, "unit_price": 120 }]
  }
}'

Common XRechnung Errors

The most frequent validation failures and how to fix them.

BR-DE-15

Missing Leitweg-ID

The buyer_reference field must contain a valid Leitweg-ID for B2G invoices.

BR-DE-17

Wrong Payment Means

XRechnung requires a payment means code. SEPA credit transfer (code 58) is the most common choice.

BR-DE-1

Missing Seller Contact

German CIUS requires seller contact details: name, phone and email.

BR-CL-10

Invalid Invoice Type

The invoice type code must use UNTDID 1001 values. Use 380 for a standard invoice or 381 for a credit note.

BR-S-08

Missing VAT Category

Each line item needs a VAT category code (S, Z, E, AE, etc.) and the correct rate.

UBL-SR

Invalid UBL Structure

XRechnung only allows the UBL Invoice or CreditNote document types. Custom extensions are rejected.

Supported Portals

Validate before you submit to any German e-invoicing portal.

ZRE

Zentrale Rechnungseingangsplattform

Federal authorities

OZG

OZG-RE

States and municipalities

State Portals

Bavaria, NRW, Baden-W., etc.

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Free sandbox. No credit card required.

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