Invoicing Austria's federal government: Why a checked file can still be rejected

The work is complete and the invoice is ready. Your invoicing software reports no errors. Yet when you submit it to Austria’s federal government, a required detail is missing — perhaps the order reference. How can an invoice that has passed a check still be incomplete?

The explanation lies in what was checked. A file can meet the general rules of its invoice format while the recipient requires additional information. With ebInterface, that distinction can be made very concrete. Understanding it helps you request the right details when you accept the order.

The following examples are based on the published rules for ebInterface 6.1, as of 4 October 2026. They describe possible situations, not actual customer submissions.

“Valid” — but for what purpose?

ebInterface defines how invoice data may be arranged in a file. The technical blueprint is called a schema. A schema check determines whether the file follows those rules.

In AUSTRIAPRO’s general ebInterface 6.1 schema, a purchase order reference for the invoice recipient is optional. An otherwise correct file can therefore pass this check without one.

For submission through e-Rechnung.gv.at, however, the order reference is mandatory. Additional rules and adapted schemas apply. ebInterface requirements

If your software simply reports “Invoice valid”, it is worth asking the provider a specific question: does the check also cover the requirements of Austria’s federal government? The answer tells you how much that result establishes for your submission.

The two identifiers to clarify before writing the invoice

The order reference, called Auftragsreferenz in German, allows your invoice to be assigned to the correct federal department. It can take several forms:

Form	Example from the federal government’s documentation
Ten-digit purchase order number	4700000001
Three-character purchasing group	Z01
Purchasing group with an additional reference	Z01:111599

When a ten-digit purchase order number is used, order line numbers are also required. They connect the individual invoice lines to the lines of the purchase order. The department that placed your order can tell you which details apply. The examples in the table are not substitute values to copy into your invoice. Federal government order reference

The supplier number, or Lieferantennummer, identifies you as a supplier in the federal government’s accounting system. It has eight digits and is also provided by the department that placed the order. According to the official documentation, neither the USP hotline nor e-Rechnung.gv.at support can supply it if you do not know it. Federal government supplier number

Both identifiers therefore come from the business relationship. Invoicing software cannot reliably derive them from your VAT number, your own customer number or the department’s name. Keeping them with the order makes them readily available when it is time to invoice.

A consolidated invoice can also cause problems

Suppose the same department places two orders with you. You want to invoice both at the end of the month. For ebInterface invoices, however, e-Rechnung.gv.at specifies that a single invoice must not refer to several purchase orders at once. Specific invoice requirements

Simply writing both purchase order numbers in a notes field does not resolve this requirement. Agree the billing arrangements with the department before finalising the invoice. A shared discount or deposit may need further discussion if the orders are to be invoiced separately.

Details visible in the preview may not be used in processing

Another difficulty is less obvious than a rejection: some additional details are not used by the recipient’s system. For ebInterface 6.1, e-Rechnung.gv.at lists extension fields among the information it ignores. Processing documentation

Imagine entering an important project identifier in a custom extension field. It appears in your preview, so the invoice looks complete. But if that field is not processed by the recipient, the identifier cannot be used for automatic matching in the way you expect.

When the department asks for a particular detail, clarify which field it belongs in as well. With an e-invoice, “included somewhere on the invoice” is not always sufficient. A concrete example invoice can make this easier to discuss than a general description of the invoicing software.

Test first — then submit the invoice for real

The official e-Rechnung.gv.at test upload is available for technical checks. You can use it to check an invoice file you have created against the test system’s requirements.

One distinction is essential: invoices uploaded to the test area are neither processed further nor paid. Even after a successful test, you still need to submit the invoice through the intended submission channel.

Preparing your first invoice to a federal department therefore involves a manageable set of steps: obtain the order reference, any required order line numbers and your supplier number. Clarify which services or goods should be invoiced together. Test the completed file and keep the result with the version you checked.

A successful check then provides useful evidence of what has been verified. Assigning the invoice to the correct order and actually submitting it remain separate steps — and deserve a final check before you consider the invoice dealt with.