E-invoicing: What is the routing ID and how do I create an e-invoice for public authorities?
Anyone who issues invoices to public authorities operates within a separate, older e-invoicing system – with the routing ID at its heart. This article explains what the routing ID is.
Introduction
If you work for a public authority or another public sector client, you may have come across terms such as ‘XRechnung’, ‘routing ID’ or ‘OZG-RE’. These belong to a distinct area of e-invoicing, and we’ll break it down for you.
A clarification first, as these concepts are often confused: e-invoicing to public authorities – known as B2G (Business-to-Government) for short – is not the same as the obligation that has applied to business-to-business transactions since 2025. It predates this and follows its own specifications.
At the heart of this area is the routing ID. This is the point where most queries arise.
This article explains what B2G means, what the routing ID is, where it is entered, and why you do not need it in standard business-to-business transactions.
What B2G means
B2G refers to invoices issued by businesses to public sector clients – that is, to government departments and public administration bodies. E-invoicing has been in use in this sector for longer than in business-to-business transactions.
For public sector clients, e-invoicing in the XRechnung format is the prescribed standard. So, anyone invoicing a public authority for a service generally issues their invoice as an XRechnung and submits it via the specified channel.
The e-invoicing requirement in the B2G sector is not new. It has been in place for invoices to federal government bodies since the end of 2020; the federal states have their own regulations and deadlines. This is to be distinguished from the requirement between businesses, which comes into force in 2025.
What is the routing ID?
The routing ID is the core element of e-invoicing to public authorities. It is a unique identifier that serves as a digital address within the administration.
It enables an incoming e-invoice to be delivered correctly, forwarded to the right department within the public authority and processed automatically. Without this information, the invoice is usually rejected by the incoming platforms. The routing ID is therefore a mandatory field on every e-invoice sent to a public contracting authority.
Where the routing ID belongs
The routing ID has a fixed position on the invoice. This is useful to know because invoicing software inserts it at this point.
In XRechnung, the routing ID is specified in the ‘Buyer Reference’ field (technically BT-10). Ensure it is spelled correctly without any unnecessary spaces, so that the invoice is not rejected. In invoicing software, the routing ID can usually be stored in the client’s profile, so that it automatically appears in the correct place on every invoice.
You do not need to come up with the routing ID yourself: the public contracting authority will provide it to you – usually in the contract or purchase order – and is obliged to do so. If it is missing, ask the contracting authority for it.
How the invoice reaches the authorities
There are prescribed methods for submitting invoices to public authorities. Which one applies depends on the specific contracting authority.
Centralised invoice receipt platforms are available for federal government bodies; the administration is increasingly switching to the OZG-RE platform. In addition, many bodies use the Peppol network for receiving invoices. Some federal states and local authorities use their own portals. You should therefore always follow the guidelines provided by your specific client; you will usually be informed in good time which method and which platform applies to you.
When dealing with businesses, you do not need a routing ID
This is the point that often causes confusion. The routing ID applies solely to dealings with public authorities.
In standard business-to-business transactions – that is, for e-invoicing in the B2B sector, which has been in force since 2025 – you do not need a routing ID. The technical field of the same name may, at most, be used for an internal reference such as a cost centre or project number, but it is not a routing ID.
Common sources of error
- Confusion between B2G and B2B: Public sector invoicing is mistakenly equated with the requirements for business-to-business transactions. Both follow their own rules.
- Assuming a routing ID is required in B2B: It is assumed that a routing ID is also necessary for transactions between businesses. It is required solely for transactions with public authorities.
- Route ID missing or incorrect: Without a correct route ID in the ‘Purchaser reference’ field, the receiving platforms will reject the invoice.
- Incorrect transmission method: The invoice is sent to the wrong platform. Please follow the specifications of the specific client.
- PDF only instead of XRechnung: A PDF is sent to a public sector client where an XRechnung is required. Ensure you use the specified format.
How we work together
For invoices to public authorities, please ensure the correct format and routing ID are used; we’ll handle the processing.
Your tasks:
- Create invoices for public authorities as XRechnung files with the correct routing ID
- Request the routing ID from the public sector client if it is missing
- Send us the invoices in their original format via the agreed channel
Our tasks:
- Understand the specific requirements of the B2G sector
- Post the invoices and process them for tax purposes
- Clearly separate B2G and B2B
We will agree the exact breakdown with you.
Frequently asked questions
What is B2G?
B2G refers to invoices issued by businesses to public sector clients, i.e. government departments and public administration bodies. E-invoicing has been in use there for longer than between businesses.
What is the routing ID?
A unique identifier that serves as a digital address within the public sector. It ensures the correct delivery of the e-invoice and is a mandatory field on every invoice sent to a public sector client.
Where do I enter the routing ID?
In XRechnung, in the ‘Buyer Reference’ field (BT-10). Invoicing software will automatically insert it here if you enter it in the client’s profile.
Where do I get the routing ID from?
From the public contracting authority. They are obliged to provide it to you, usually in the contract or purchase order. If it is missing, ask for it.
Do I need a routing ID for invoices to other businesses?
No. A routing ID is not required for business-to-business transactions. In such cases, the technical field can only be used for internal reference purposes. \[Link zu einem Hilfsartikel]
How do I send invoices to public authorities?
Via the platform specified by the contracting authority; central receipt platforms are available for the federal government, and many agencies also use Peppol. Please follow the guidelines provided by your specific contracting authority.
Legal notice
This article provides an overview and is not a substitute for individual advice. Requirements in the B2G sector vary depending on the contracting authority; the current legal situation and the requirements of the respective public contracting authority are decisive.
If you have any questions about invoices to public authorities, please contact us directly.
As at: June 2026