Germany Updates E-Invoicing Rules: New MOF Guidance 2025

On October 15, 2025, the German Ministry of Finance (MOF) released a second administrative guidance letter to address ongoing uncertainties surrounding the mandatory e-invoicing regime for domestic B2B transactions, which has been in force since January 1, 2025. The latest guidelines follow the previous one released in October 2024, as well as the FAQ document from February this year.

The Scope and the Purpose of the Guidance

The guidance provided by the MOF refines the interpretation of existing rules, amends the German VAT Application Decree, and introduces crucial clarifications on the classification and legal impact of various invoice errors, as well as the role of e-invoice validation. The German MOF divided errors into three categories: formatting errors, business rule errors, and content errors.

Formatting errors arise when an invoice file fails to meet syntax or technical standards, making it non-compliant as an e-invoice. As a direct result of such errors, correct data extraction is not possible. However, these errors can be identified through validation software.

Business rules errors refer to the logical inconsistencies within the data, such as mismatches between VAT values or missing non-mandatory fields like the “Buyer reference.” Although their impact is lower than the formatting errors, errors in mandatory fields still affect compliance. Finally, content error concerns inaccuracies in the legally required invoice details defined under sections 14(4) and 14a of the VAT Act. As a consequence the invoices are non-compliant even when no error is detected during validation.

Regarding validation, the guidance underlines that although validation tools can confirm whether an invoice meets the EN 16931 standard, the issuer’s validation is not sufficient by itself. Recipients must still review the content for accuracy. Therefore, proper due diligence supported by a retained validation report contributes to recipients' trust in the invoice format and business rule compliance.

Additionally, the MOF emphasized the importance of including all the mandatory invoice details directly in the structured e-invoice data, adding that referencing attachments or external links is unacceptable. Notably, the guidance highlights the retention requirement, which mandates that incoming and outgoing invoices must be kept for eight years.

Conclusion

The guidance applies to all transactions after December 31, 2024, with transitional measures lasting until the end of 2027. Ultimately, it should contribute to a more stabilized e-invoicing framework and ensure consistent implementation across businesses. Businesses now have a clearer understanding of the taxonomy of error and retention requirements, which can help them adapt their invoicing systems, improve data accuracy, and maintain trust in automated tax processes.

Source: Deloitte, VATabout