XRechnungen rejected: Leitweg-ID and buyer reference

Distinguishing buyer reference, Leitweg-ID and order reference

These three terms are often confused, but they do not mean the same thing:

• Buyer reference (BT-10): an identifier that the recipient assigns for its internal allocation. For public-sector clients, this is exactly the Leitweg-ID (the routing ID used by German public authorities). In the data model, it is the buyerReference.buyerReferenceId field.
• Order reference (BT-13): the buyer's order or purchase order number, so that the buyer can match the invoice to their order. In the data model, buyerReference.IssuerAssignedID. This is not the Leitweg-ID.

So the Leitweg-ID is not a separate field next to the buyer reference, but the value that public-sector clients ask you to enter in the buyer reference.

When is the Leitweg-ID required?

The Leitweg-ID is not strictly required. For an XRechnung, faktoora checks that at least one of the following fields is present:

• Leitweg-ID / buyer reference (BT-10)
• Email address of the recipient
• Contact person of the recipient with email
• PEPPOL ID of the recipient

So as long as you have stored a valid email address for the recipient, the Leitweg-ID is not required.

What to do if the recipient has no Leitweg-ID?

If the invoice recipient does not have a Leitweg-ID (typically private companies), you do not need to enter a Leitweg-ID. It is sufficient to specify the recipient's email address or PEPPOL ID in the XRechnung.

In this case, the "Leitweg-ID" or "Buyer reference" field in faktoora remains empty.

Which value goes where?

If in doubt, ask the recipient which identifier they expect, and enter it in the matching field:

For public-sector clients, an order number in the buyer reference means that the invoice cannot be allocated; that is where the Leitweg-ID belongs.

Common reasons for rejected XRechnungen

Rejection by faktoora during creation

If faktoora shows an error message during creation, check:

• Missing contact details: make sure you have provided at least one of the following details for the recipient: email address, Leitweg-ID, PEPPOL ID or contact person with email
• Missing or invalid VAT ID: if you specify the recipient's VAT ID, it is checked and must match the expected format
• Invalid field formats: IDs and references must be structurally correct

Rejection by the recipient platform

If faktoora accepts the XRechnung but the recipient platform (Peppol network, EDI system or the recipient's business system) rejects the invoice, the cause lies outside faktoora:

• The recipient applies stricter rules than the EU standard EN 16931
• The Leitweg-ID or buyer reference is not registered or not valid in the recipient's system
• The system rejects the invoice for business reasons (e.g. authentication error, missing approval, record not found)

In these cases, contact the invoice recipient to clarify:

• Which Leitweg-ID or reference exactly do they expect?
• Is the account or supplier record correctly registered in their systems?
• What exact error message does their system show?

faktoora cannot anticipate the internal requirements of other organizations; each institution performs its own checks.

KoSIT validation report

The KoSIT validation report of the Coordination Office for IT Standards (KoSIT) is a validation system for checking German XRechnungen. It checks compliance with national and European standards (EN 16931).

If a recipient rejects an invoice with a "KoSIT error", this means that the file violates the expected structure, for example:

• Format or structural errors in the XML
• Missing or incorrectly formatted required fields
• Invalid combinations of values (e.g. the tax rate does not match the tax category)

faktoora already checks XRechnungen against these standards during creation. If you still receive a KoSIT error message from the recipient:

1. Check that all required fields are filled in correctly
2. Validate the tax categories and rates (see section below)
3. Contact the invoice recipient and ask for the exact error message
4. If necessary, contact faktoora support

Checking tax category and tax rate

A common source of errors is the combination of tax category and tax rate. EN 16931 has rules on which rates match which categories:

• Tax category "Standard" (S): typically expects positive tax rates (e.g. 19% or 7% in Germany)
• Tax category "Reduced" (AA, AE, etc.): reduced or special rates
• Tax category "Exempt" (E): the tax rate must be 0%

For example, if you use tax category "Standard" with a tax rate of 0%, many validators and recipient systems reject this combination. Use "Exempt (E)" with 0% instead.

Corrections afterwards

If you discover after sending that details were wrong:

• An XRechnung that has already been created cannot be corrected afterwards
• You must create a cancellation invoice (which reverses the incorrect invoice) and a corrected invoice (with the correct data)
• Both invoices are documented and can be sent

See also: Cancellation / credit note for existing invoices.