Germany’s New E-Invoicing Guidance: What the BMF Clarified, and What It Means for 2027

Germany’s Federal Ministry of Finance (BMF) published new guidance on the B2B e-invoicing mandate last week, about ten weeks before large businesses have to start issuing e-invoices. The letter is dated October 15, 2026, and builds on the BMF letters from October 2024 and October 2025.

It covers what happens when an e-invoice fails a validation rule, how much detail the structured data needs, and how to treat invoices issued around the start date. It also adds some transitional relief. The deadlines stay the same.

A quick reminder of where the mandate stands

Since January 1, 2025, every business in Germany has had to be able to receive e-invoices that comply with EN 16931, usually in XRechnung or ZUGFeRD format. The issuing obligation comes in two waves. Businesses with turnover above €800,000 in the previous calendar year must issue compliant e-invoices for domestic B2B transactions from January 1, 2027.

Everyone else follows on January 1, 2028. The new letter keeps these dates. Its focus is on how the rules apply in practice.

What the BMF clarified

A technical error doesn’t automatically invalidate an invoice

The BMF separates technical validation, including the EN 16931 business rules, from validity for tax purposes. A business rule error does not, on its own, make an e-invoice invalid for VAT. An invoice only becomes invalid automatically when the failed rule concerns tax-relevant fields, and the letter asks service providers and software vendors to classify their validation rules accordingly.

So a file that can be processed and has complete, correct VAT information still supports input VAT deduction, even if a validator flags a non-tax issue. To benefit from this, your process needs to know which validation errors touch VAT fields and which don’t.

The structured data is what counts

The structured part of the e-invoice, not the human-readable PDF, has to carry the information needed to check the tax treatment: the type, scope and content of the supply, and its location. Mandatory VAT details belong in the designated structured fields, not in free text.

The tax authorities recommend the KoSIT and FeRD mapping tables to align that data with EN 16931.

If the description in the structured data isn’t detailed enough to assess the VAT treatment, the buyer’s input VAT deduction is at risk.

Corrections, attachments and public bodies

Invoice corrections have to be issued in a structured format, although the BMF still accepts flexible ways of making the correction itself. Supporting detail, such as itemized timesheets, can travel as an attachment, but it has to be embedded in the e-invoice. A separate file sent alongside it in the same email doesn’t count.

Invoices to public bodies fall under the VAT e-invoicing rules only where the authority acts in a business capacity. Separate public procurement invoicing rules may still apply, and public fee assessments can keep using standard invoice formats until June 2030.

Where the BMF made things easier

The letter also includes several transitional arrangements:

• Advance invoices issued before your own start date don’t need to be reissued electronically, even if the supply is completed or paid after the mandate applies to you.
• Final invoices can summarize earlier partial payments in structured field BT-113 until the end of June 2030, with the detailed breakdown in free text or an embedded attachment.
• For construction services, sellers can show trade summaries in the structured data and attach the full service specification.
• Gross-price invoices with rounding differences can show summary totals in the structured format until December 2027, as long as human-readable line items supporting the summary are attached.
• Standard discount agreements only need a general reference in the invoice, provided the underlying records are easy to verify.

No fines, but non-compliance still has consequences

The letter confirms that no administrative fine currently applies for issuing an invoice that isn’t EN 16931-compliant, or a paper or PDF invoice where an e-invoice is required.

Non-compliant invoices can still cause problems in tax audits, in corrections and in input VAT deduction. That last one affects your customers: they may lose the deduction on invoices you sent them, so expect them to ask for compliant e-invoices from January regardless.

What to do before January

If your turnover was above €800,000 last year, January 1, 2027 is about ten weeks away, with the holidays in between. The new guidance helps with some specific cases, but most of the preparation work is the same. Before the end of the year:

1. Confirm which wave you belong to, based on last year’s turnover, and plan around that date.
2. Check that your structured data, not just the PDF, carries every mandatory VAT detail in the right EN 16931 fields.
3. Look at how your validation process handles errors, and make sure it separates tax-relevant failures from technical ones.
4. Review how you issue corrections, final invoices after advance payments, and invoices with supporting attachments, and make sure attachments are embedded.
5. If you work in construction or invoice in gross prices, check whether the transitional relief applies to you, and note when it ends.
6. Test real invoice flows with a few customers before the deadline, not in the final week.

How Babelway helps

Babelway is an EDI, Peppol and B2B integration platform with 18 years of experience, used by more than 700 customers in 26 countries to exchange over 650 million messages a year with 99.99% service availability. It connects to your existing ERP or accounting system and converts your current output into compliant XRechnung or ZUGFeRD e-invoices, and validates invoices before they reach your customers.

You can start a 30-day free trial through the self-service platform, with no sales call required, and connect your first channel the same day. Or you can talk to our team about your setup and the gaps specific to your ERP. The same platform also covers e-invoicing in France, Belgium and Poland, if you need other countries later.

This article summarizes the BMF letter of October 15, 2026 for general information and is not tax advice. Check the letter itself and speak with your tax advisor before making changes to your invoicing process.