In order to cover sector-specific areas of application, EU member states can expand the semantic data model of European standard EN 16931 using extensions. This has been possible in Germany since 1 January 2021. The XRechnung extension makes it possible to add several sub invoice lines below a single invoice line. The extension also allows XML files to be embedded in the invoice as attachments.

Sub invoice lines are data elements which provide more detailed information about the individual invoice lines they come under. This makes it possible to add several sub invoice lines below a single invoice line, for example to reflect contractual specifications. An example of the hierarchy of invoice lines and sub invoice lines is given below:

To include sub invoice lines, you must use the XRechnung extension. The extension has been valid since 1 January 2021 as version 2.0.0 of the XRechnung specification. For more information about the XRechnung extension, please see the website of the Coordination Office for IT Standards (KoSIT).

The XRechnung extension is especially relevant for the construction industry, but other industries can benefit from it as well.

Although the XRechnung standard already makes it possible to submit invoice types which are specific to the construction industry (interim invoices, partial invoices, final invoices), the XRechnung extension covers additional industry-specific requirements. For example, the XRechnung extension makes it possible to embed XML attachments and thus add GAEB files[1] to your invoice as supporting documents. In addition, invoice lines can be structured so that the sub invoice lines can be used to show specifications.

[1] GAEB files are based on a uniform standard agreed on for exchanging information in the construction industry. This standard expands, harmonises and improves all the requirements for electronic processes with regard to construction work ( https://www.gaeb.de/en/).

The OZG-RE invoice submission platform has accepted the current standard and the XRechnung extension since 1 January 2021, so if the XRechnung extension is relevant for you, it is possible to use it on the platform. However, before using the XRechnung extension, the invoice issuer and the invoice recipient should communicate with each other to avoid any difficulties with formats to be used.

If you create invoices using the web submission form on the invoice submission platform, under the tab “Invoice lines” you can select the button “Add sub invoice line” to add more sub invoice lines, as shown in figures 2 and 3 below. Under the tab “Attachments” you can embed XML files in the invoice as supporting documents. In this way, you can create an XRechnung extension.

If you submit invoices using the web upload function on the invoice submission platform, you can submit completed e-invoices compliant with the XRechnung extension using the upload function. If you have further questions about creating e-invoices, please contact your software provider.

If you submit invoices using email or Peppol, you can submit completed e-invoices compliant with the XRechnung extension using those transmission methods as well. If you have further questions about creating e-invoices, please contact your software provider.ler.