How to Obtain and Verify a Leitweg-ID – Complete Guide

The Leitweg-ID is the most common stumbling block in XRechnung submissions to government authorities. Without it, KOSIT validation fails with the critical error BR-DE-2 – and the invoice is rejected by the portal before any human ever sees it. This guide explains what the Leitweg-ID is, where to find it, how to verify it, and how to avoid typical errors.

What Is the Leitweg-ID and Why Is It Mandatory?

The Leitweg-ID (routing identifier, also called Buyer Reference) is a unique numerical identifier assigned to each German government entity or cost center for invoice processing. For XRechnung it replaces the earlier manual routing of paper invoices: the electronic invoice receipt system reads the Leitweg-ID from field BT-10 and automatically routes the invoice to the responsible case handler or accounting unit.

CIUS DE business rule BR-DE-2 makes BT-10 a mandatory field for all XRechnungen to German authorities. For B2B invoices between private companies BT-10 is optional – it can be used there for other buyer references (order number, project number).

The Leitweg-ID Format

A Leitweg-ID consists of three segments separated by hyphens. Example: 04011000-1234512345-06

• Segment 1 – Area code: Two-to-eight-digit numerical code identifying the federal state or administrative area. 0 = federal level, 01 = Schleswig-Holstein, 02 = Hamburg, 03 = Lower Saxony, 04 = Bremen, 05 = North Rhine-Westphalia, 06 = Hesse, 07 = Rhineland-Palatinate, 08 = Baden-Württemberg, 09 = Bavaria, 10 = Saarland, 11 = Berlin, 12 = Brandenburg, 13 = Mecklenburg-Vorpommern, 14 = Saxony, 15 = Saxony-Anhalt, 16 = Thuringia.
• Segment 2 – Institution code: Numerical code identifying the specific authority or department within the area. Length varies by authority.
• Segment 3 – Check digit: Two-digit check digit calculated from the preceding segments using a defined algorithm.

Step 1: Extract Leitweg-ID from Contract or Purchase Order

The simplest route: look in your contract, framework agreement, service agreement, or purchase order with the authority. German authorities are obliged to state the Leitweg-ID in procurement documents. You will typically find it under headings such as Leitweg-ID, Rechnungsadressate, Routing-ID, or Buyer Reference.

Step 2: Search for Leitweg-ID on the Authority's Website

Many federal ministries, state authorities, and municipalities publish their Leitweg-IDs on their official websites. Search the authority's website for terms such as E-Rechnung, Leitweg-ID, or elektronische Rechnungsstellung. The information is often found in sections titled Beschaffung, Einkauf, or Für Lieferanten.

Step 3: Use the Leitweg-ID Registry

The central Leitweg-ID registry is available at leitweg-id.de. There you can search by authority name, city, or federal state. The registry is operated by FIFO GmbH (Forschungsinstitut für Innovation und Organisation) and contains the Leitweg-IDs of most federal, state, and municipal authorities.

Step 4: Contact the Authority Directly

If you cannot find the Leitweg-ID yourself, contact the authority. Do not approach the project department but directly the accounting or invoice receipt office (Rechnungswesen, Kreditoren, Finanzabteilung). State your request clearly: you need the Leitweg-ID (BT-10 / buyer reference) for creating an XRechnung.

Step 5: Verify the Leitweg-ID for Correctness

Once you have a Leitweg-ID, verify it for formal correctness. A valid Leitweg-ID must satisfy the following conditions:

• Format: Three segments separated by hyphens, e.g. XX-XXXXXXXXXX-XX.
• Only digits in each segment – no letters, no special characters.
• Check digit: The third segment is a two-digit check digit. Our Leitweg-ID verification tool at docutools.pro/tools/leitweg calculates and verifies this automatically.
• No leading spaces, no trailing spaces – the Leitweg-ID must appear in the BT-10 field exactly as given.

Step 6: Enter the Leitweg-ID in the XRechnung

Enter the Leitweg-ID in field BT-10 (Buyer Reference). In UBL syntax: <cbc:BuyerReference>04011000-1234512345-06</cbc:BuyerReference>. In CII syntax: <ram:BuyerReference>04011000-1234512345-06</ram:BuyerReference>. Ensure there is no space before or after the Leitweg-ID.

The Most Common Leitweg-ID Errors

• Leitweg-ID completely forgotten (BR-DE-2): The most common problem. Solution: Always check that BT-10 is filled.
• Copied incorrectly: A transposed digit or a missing hyphen causes rejection by the check digit validation.
• Outdated Leitweg-ID: Authorities can change Leitweg-IDs when departments are reorganized. Verify the ID with every new contract.
• Wrong department ID: Large ministries often have multiple Leitweg-IDs for different departments. Use the ID that applies to your project.
• Leitweg-ID in wrong field: BT-10 (Buyer Reference) is not the same as BT-46 (Buyer identifier) or BT-13 (Order reference).
• Order number instead of Leitweg-ID in BT-10: Order numbers belong in BT-13 (Order reference), not BT-10.

Federal Authorities and the ZRE

All federal ministries and subordinate federal agencies use the ZRE (Zentrale Rechnungseingangsplattform) at xrechnung.bund.de. Federal authorities have Leitweg-IDs that always start with 0-. The federal Leitweg-ID directory can be viewed at xeinkauf.bund.de. The ZRE also accepts De-Mail submissions – in this case, the Leitweg-ID must also be entered in the BT-10 field of the XML file.