Leitweg-ID for Companies: Do You Need One for B2B Invoices?

There is no Leitweg-ID for companies: a Leitweg-ID addresses only invoice recipients in the German public sector. Businesses do not need one, not even for the B2B mandate in force since 1 January 2025. On an XRechnung to a company, the buyer reference field BT-10 must still be filled because of rule BR-DE-15, with the reference your customer gives you.

This guide is for finance and ERP teams, including foreign suppliers, who see a mandatory "Leitweg-ID" field in their invoicing software or get asked for one by a German customer. It explains who actually has a Leitweg-ID, what belongs in BT-10 on B2B invoices, and how to check the file before you send it.

Who owns a Leitweg-ID?

A Leitweg-ID is the electronic address of a German public-sector invoice recipient, read from BT-10 by the receiving platform to route the invoice to the right office. Its structure and check digit are covered in What Is a Leitweg-ID?; this article answers the question of who has one.

For the federal level, the legal basis is the e-invoicing ordinance (E-Rechnungsverordnung, ERechV). Section 5(1) No. 1 ERechV (opens in a new tab) requires an e-invoice to the federal administration to contain "eine Leitweg-Identifikationsnummer" (a Leitweg identification number). Under Section 2(4) ERechV (opens in a new tab), invoice recipients are the bodies listed in Section 159(1) Nos. 1 to 5 of the Act against Restraints of Competition (GWB): the Federation and the public contracting authorities assigned to it. Companies appear in the ordinance only as invoice issuers (Section 2(3) ERechV).

The federal e-invoicing FAQ (opens in a new tab) is explicit. It says that companies and invoice issuers "grundsätzlich keine eigene Leitweg-ID" need, "auch nicht" for the B2B e-invoicing obligation that has applied since 1 January 2025. In English: as a rule, no company needs its own Leitweg-ID, and the B2B mandate does not change that.

How does routing work in B2G and in B2B?

The difference is who issues the reference and what it is for. In the public sector (B2G) the flow is:

1. The authority receives its Leitweg-ID from the responsible office, at federal level from the Central Finance Office of the Federation.
2. It passes the ID to the supplier, usually in the purchase order or contract.
3. The supplier copies it unchanged into BT-10 (UBL cbc:BuyerReference, CII ram:BuyerReference).
4. The platform, for federal bodies the OZG-RE, reads BT-10 and forwards the invoice to the responsible office.

In B2B there is no central platform and no numbering scheme. EN 16931 defines BT-10 as an identifier assigned by the buyer for internal routing. The customer decides what it should contain: a cost centre, a project code, a department code or the name of the person who placed the order. The invoice itself travels over whatever channel you agreed, such as e-mail or Peppol.

When does a company have a Leitweg-ID after all?

"Company" and "public contracting authority" are not mutually exclusive. Under Section 99 No. 2 GWB (opens in a new tab), legal persons governed by private law are public contracting authorities if they were set up to meet needs in the general interest that are not industrial or commercial, and the state mostly finances, supervises or appoints them. Sector contracting entities under Section 100 GWB, for example in energy or water supply where public bodies hold a controlling influence, are a second group.

A publicly owned GmbH can therefore be an invoice recipient under the ERechV or a state law and have a Leitweg-ID for its incoming invoices. Do not try to work this out from the commercial register. What counts is whether the customer gives you a Leitweg-ID. That ID belongs to the customer. Your own invoices to other businesses never carry a Leitweg-ID of your company.

What goes into BT-10 on a B2B invoice?

Whether BT-10 must be filled depends on the format, not on VAT law:

BR-DE-15 only checks that a non-empty value is present. A field containing only spaces fails. A placeholder such as "-" passes technically, but it does not help your customer's accounts payable team match the invoice. Which ZUGFeRD profiles count as e-invoices is explained in ZUGFeRD Profiles and Versions.

A practical order for filling BT-10 on B2B invoices:

1. If the customer specified a reference (purchasing terms, purchase order, supplier portal), use exactly that.
2. If there is none, ask their accounts payable team what their invoice check needs for matching.
3. Until they answer, enter something they can match, such as the name of the person who ordered. The purchase order number also goes into BT-13.

Worked example: three invoices, three BT-10 values

Muster GmbH (VAT ID DE123456789) issues three XRechnung invoices on the same day.

In UBL, the buyer reference of the second invoice sits directly under the root element:

<cbc:DocumentCurrencyCode>EUR</cbc:DocumentCurrencyCode>
<cbc:BuyerReference>KST-4711</cbc:BuyerReference>
<cac:OrderReference>
  <cbc:ID>PO-88213</cbc:ID>
</cac:OrderReference>

All three files pass BR-DE-15. Only the first contains a Leitweg-ID, so only there do format and check digit matter. KST-4711 is not a Leitweg-ID and is not meant to be one: a Leitweg-ID checker correctly reports that the coarse address may only contain digits. The other required fields with their XML paths are listed in XRechnung Mandatory Fields.

What happens if BT-10 is missing on a B2B invoice?

Technically the file fails. BR-DE-15 has the level "fatal", so an XRechnung without BT-10 is not acceptable under the KoSIT rules. Many inbound systems apply exactly these rules and reject the file automatically.

For VAT the answer is different. The BMF letter of 15 October 2025 names the missing "BT-10 Buyer reference" as its example of a business rule error that concerns content other than the mandatory invoice details, and such errors are irrelevant for VAT purposes. The invoice remains an e-invoice, and the customer's input VAT deduction (Vorsteuerabzug) does not depend on BT-10. How format errors, business rule errors and content errors differ is explained in E-Invoice Format Error, Business Rule Error or Content Error?.

In practice, a missing buyer reference will not cost your customer a tax deduction, but it may delay your payment while the file sits in their exception queue.

Leitweg-ID, buyer reference, order number, Peppol ID: the differences

According to the federal e-invoicing FAQ, the VAT identification number and the Global Location Number (GLN) are registered Peppol identifier schemes for companies in Germany, while public bodies use their Leitweg-ID with the prefix 0204. When a German business customer asks for "your Leitweg-ID", they usually mean one of these identifiers or the buyer reference.

How to check BT-10 with docutools.pro

1. Find out what the reference is. If a customer calls a number their "Leitweg-ID", open the Leitweg-ID validator, enter it in the "Validate" tab and click "Validate". A real Leitweg-ID shows "Valid" and a "Segment Analysis" of coarse address, fine address and check digit. A B2B reference such as KST-4711 returns "Coarse address may only contain digits (0–9)." The tool runs in your browser and checks structure and check digit, not whether the ID is registered.
2. Create the invoice. In the XRechnung generator, enter the value in the "Buyer reference / Leitweg-ID" field of the "Company" step. If you leave it blank, the generator writes the invoice number into BT-10 so that BR-DE-15 is met. For invoices to authorities, that does not replace the Leitweg-ID.
3. Check the finished file. Upload the XML to the XRechnung validator. The file is sent to our server for the check. The "KoSIT validation" checks the way the KoSIT validator does (configuration 2026-08-31); if BT-10 is missing, the result is "Not KoSIT-conformant" with BR-DE-15. The free tier allows 2 uploads per day; the Pro plan has no daily limit.
4. Read the rule. The explanation and where to add the element in the XML are on the BR-DE-15 page of the XRechnung error codes reference.

The viewer does not show BT-10 in its "Extracted data" table. To see the value itself, open the file in the XML viewer and look for cbc:BuyerReference. If you supply a German authority and still need its ID, see How to Find or Get a Leitweg-ID; more articles are in the XRechnung guides.

Sources

• Section 5 ERechV: content of the e-invoice (opens in a new tab) and Section 2 ERechV: definitions (opens in a new tab) (German)
• Section 99 GWB: public contracting authorities (opens in a new tab) and Section 100 GWB: sector contracting entities (opens in a new tab) (German)
• Federal e-invoicing FAQ, sections Leitweg-ID and Peppol (opens in a new tab) (German)
• BMF letter of 15 October 2025 on mandatory e-invoicing (opens in a new tab) (German)
• KoSIT validator configuration for XRechnung (rule BR-DE-15) (opens in a new tab) and Peppol BIS Billing 3.0, rule PEPPOL-EN16931-R003 (opens in a new tab)

Last reviewed: October 2026

This article is general information, not tax or legal advice.