BMF guidance on e-invoicing: what format errors, business rule errors and content errors really mean

5. Accepting or rejecting an e-invoice

Under the BMF guidance of 15 October 2025, whether an electronic invoice must be accepted or rejected depends on the type of error.
The key distinction is between a format error, a content error and a non-compliant invoice under the German VAT Act.

Step 1 — Format validation

First, check whether the file technically and formally meets EN 16931 requirements.

• Result: e-invoice
  The file is technically correct and contains all mandatory EN 16931 details → Continue with content checks.
• Result: other electronic invoice
  The file contains format errors, such as missing or misplaced mandatory fields.
  • If the issuer is not yet required to use e-invoicing, the recipient may accept or reject it.
  • If the issuer is already subject to the obligation, the recipient must reject it because it is not an e-invoice in the legal sense.

Step 2 — Content checks

Next, check whether the invoice is correct in its tax treatment, arithmetic and facts.
Content errors may be detected technically or identified manually.

1. Content that can be checked technically or by rules
   – Business rule checks using a validation tool
   – Typical errors: incorrect tax rates, invalid code-list values, missing mandatory fields
   – Result: usually an automatic error message in the validation report
2. Content requiring substantive or manual checks
   – Checks in the ERP system or by visual review
   – Typical errors: incorrect tax treatment, incorrect amounts, erroneous service descriptions
   – Result: content errors that may or may not be relevant to tax

Step 3 — Assessing statutory correctness and civil-law requirements

An invoice is non-compliant only if
a statutory mandatory detail under §§ 14 or 14a UStG is missing or incorrect.

• Non-compliant invoice → rejection required
  Examples: missing tax number, incomplete buyer address, incorrect tax rate
• Other content error → civil-law review required
  Examples: incorrect price or order number

Other content errors are irrelevant for VAT purposes but may still matter under civil law.
If the issuer and recipient have agreed to use a particular format, such as XRechnung,
its business rules and mandatory fields should also be respected.

Example:
If the mandatory BT-10 buyer reference required by XRechnung is missing,
the invoice may be rejected on civil-law grounds,
even though the omission is irrelevant for VAT purposes and the invoice may remain valid for tax.

Not every content error is automatically a tax issue,
but it may still justify rejection on contractual or organisational grounds.

Decision matrix

Practical recommendations

1. Use a validation tool covering format and business rule checks under EN 16931.
2. Add manual or ERP-supported checks to identify factual and tax errors.
3. Consider contractual and civil-law agreements on the invoice format used, such as XRechnung.
4. Keep validation reports as evidence of due care for the tax authorities.

6. Extracts from the BMF guidance and disclaimer

The following passages are translated from the BMF guidance of 15 October 2025 and explain
how format errors and content errors should be understood in law.

Format error

Paragraph 6a
1 A file [with] […] format errors […] constitutes […] an other invoice in a different electronic format.
2 Format errors occur when the invoice file does not […]
3 […] meet the condition in § 14(1), sentence 6 UStG.

§ 14(1), sentence 6 UStG defines the following permitted formats:

• a) Formats complying with European standard EN 16931 and its UBL and CII syntaxes, and
• b) Interoperable formats supporting the future reporting system.

Meaning:
A file containing format errors does not meet EN 16931 technical requirements.
It is therefore not an e-invoice but an other electronic invoice.
Format errors initially determine only whether the document is an e-invoice or an other electronic invoice,
not whether it is correct for tax purposes.

Content errors — paragraphs 6b and 35a

Paragraph 6b

1 […] (business rule errors) […]
2 […] occur when the invoice file breaches the business rules applicable to that e-invoice format.

Paragraph 35a

1 A breach of the mandatory VAT details under §§ 14(4) and 14a UStG results in a non-compliant invoice […].
2 Such […] (content errors) may be identified in an e-invoice […] as violations of […] business rules […].
3 Business rule errors relating to other content […] are irrelevant for VAT purposes.
4 Content errors may […] exist where […] no business rules have been breached and […] validation has detected no error.
5 E-invoice validation does not replace the recipient’s obligation to check the invoice for completeness and correctness […], but supports that check.
6 A business exercising the due care of a prudent merchant may rely on the technical result of validation, as regards format and business rules, by a suitable validation application.
7 Keeping the validation report is advisable as evidence.

Meaning:

• Business rule errors breach rules defined in EN 16931 or a CIUS/extension, such as XRechnung or ZUGFeRD.
• Content errors occur when an invoice is incorrect in its tax treatment, arithmetic or facts.
• An invoice is non-compliant only when mandatory details under § 14 UStG are missing or incorrect.

The BMF also clarifies:

“Business rule errors relating to other content are irrelevant for VAT purposes.”

This means:
Not every error automatically causes the loss of input VAT deduction.
An invoice that is technically or organisationally incorrect but fully completed may still be correct for VAT purposes.

The recipient’s obligations

“E-invoice validation does not replace the recipient’s obligation to check the invoice for completeness and correctness, but supports that check.”

“A business exercising the due care of a prudent merchant may rely on the technical result of validation, as regards format and business rules, by a suitable validation application. Keeping the validation report is advisable as evidence.”

Conclusion:
Businesses may rely on the results of a suitable validation tool,
but remain obliged to check the invoice’s content.
The validation report provides important evidence of due care.

Disclaimer

Notice:
The statements in this article are made to the best of our knowledge and belief.
They constitute neither tax nor legal advice and are not binding.
For a binding assessment, please consult a tax adviser or lawyer you trust.

Andreas Pelekies

Managing Director of valitool GmbH, co-founder of FeRD and co-author of EN 16931. The ZUGFeRD format was developed under his technical leadership.