Germany's mandatory B2B e-invoicing regime has been phasing in since 2025, and the next hard step is close: from 1 January 2027, companies above €800,000 in prior-year revenue must issue domestic B2B invoices as structured e-invoices. A year later, the obligation covers everyone.
The uncomfortable part isn't the rule — it's the readiness gap. DATEV's CEO has publicly warned that a large share of smaller and mid-sized companies still isn't focused on the topic at all. And the single most widespread misunderstanding is doing quiet damage in the meantime: most companies believe that because they already send invoices as PDF attachments, they're basically done. They aren't — a PDF is not an e-invoice.
This guide covers what's already mandatory, what changes in 2027 and 2028, the two formats that actually count, where the real financial risk sits, and a realistic implementation plan that doesn't end in a December scramble.
In short: since 1 January 2025, every German company must be able to receive structured e-invoices — that part has no transition period and applies right now. From 1 January 2027, companies with more than €800,000 prior-year revenue must also issue domestic B2B invoices as e-invoices; from 1 January 2028, everyone must. Only structured, machine-readable XML formats count — XRechnung and ZUGFeRD — and a plain PDF does not qualify. The practical risk isn't a fine for the format itself: it's disrupted processes and, on the receiving side, putting VAT input deduction at risk when invoices don't meet the requirements. The fix is a scoped project of a few weeks — if it's started now, not in December.
Why e-invoicing is suddenly urgent
The regime isn't new — reception has been mandatory since January 2025 — but 2026 is the year the comfortable middle of the transition ends. From the vantage point of mid-2026, the 2027 issuing mandate is months away, and the companies that treat it as an IT afterthought will discover that invoicing touches everything: the ERP or invoicing tool, the order-to-cash process, the tax advisor hand-off, and every customer and supplier relationship that runs on documents. DATEV — the company that processes a huge share of German invoices — has been unusually direct about it: in its leadership's public assessment, the topic still isn't on the radar for a majority of smaller companies. Being early here is cheap. Being late is a process fire drill with a legal deadline attached.
The timeline to 2027 and 2028: what's mandatory when
| Date | Obligation | Who it applies to |
|---|---|---|
| Since 1 Jan 2025 | Receive, process and archive structured e-invoices — no transition period | Every German company, regardless of size |
| From 1 Jan 2027 | Issue domestic B2B invoices as e-invoices | Companies with prior-year revenue above €800,000 |
| From 1 Jan 2028 | Issue e-invoices — transition periods end | All companies, all domestic B2B transactions |
Note what's easy to miss in that table: the reception obligation is not a 2027 topic. It has applied to every company — including the smallest — since the start of 2025. A company that can't properly receive and archive a structured e-invoice today is already behind, not early.
Why a PDF is not an e-invoice
This is the myth that needs killing. Under the German rules, an e-invoice is exclusively a file containing structured, machine-readable XML data that a system can process automatically. A PDF — however professional it looks, however digitally it's delivered — is unstructured from a machine's perspective. It's a picture of an invoice, not data. Emailing PDFs is precisely the practice the regime is designed to replace, which means "we already invoice digitally" is, for most companies, a false sense of readiness. If your outgoing invoices are PDFs and your incoming invoices land in a mailbox for someone to retype, the 2027 mandate applies to you in full.
XRechnung and ZUGFeRD: the two formats that count
Two format families satisfy the German requirements:
- XRechnung — a pure XML format: all data, no visual layer. It's the standard in public-sector invoicing and fully machine-readable end to end. Current version at the time of writing: 3.0.2.
- ZUGFeRD — a hybrid: a normal-looking PDF with the structured XML embedded inside it. Humans see a familiar invoice; systems read the embedded data. Current version: 2.4. For many smaller companies, this is the gentler migration path because the visible document doesn't change.
Which one to use is mostly a question of what your customers and your systems handle best — many setups end up issuing ZUGFeRD to businesses that like a visual document and XRechnung where it's required or requested. The important part: both are real e-invoices; a plain PDF is neither.
The €800,000 question: which deadline applies to you
The 2027 issuing mandate turns on one number: prior-year revenue above €800,000. Above it, your issuing deadline is 1 January 2027. At or below it, you may keep using the transition until the end of 2027 — but from 1 January 2028 the obligation covers everyone regardless of size. Two practical implications: first, a growing company near the threshold should plan for the earlier date rather than betting on staying under it. Second, the threshold buys time on issuing only — the reception obligation has applied to every company since 2025 either way.
VAT deduction: where the real financial risk sits
There is no format police issuing instant fines for a wrongly formatted invoice. The financial exposure is quieter and mostly sits on the receiving side: where the rules require an e-invoice, a non-compliant document is, in the strict sense, not a proper invoice — and VAT input deduction depends on holding a proper invoice. Incorrect formats can mean delays, corrections, and in the worst case questions about the deduction itself. The precise tax consequences in specific cases are your tax advisor's territory, and worth one focused conversation as part of the transition — what belongs to the finance function is making sure the process produces and receives compliant documents in the first place, so the question never arises.
What "reception-ready" actually means
Being able to receive an e-invoice doesn't mean having an email address. It means: a defined channel where structured invoices arrive, software that can read and validate the XML (not just display a PDF), a workflow that gets the data into the accounting system without retyping, and archiving that preserves the structured original in compliance with German record-keeping rules. Many companies technically "receive" e-invoices today by printing them or forwarding them into a folder — which defeats the purpose and quietly builds a backlog of documents that were never properly processed.
The implementation plan: weeks, not days
| Phase | What happens |
|---|---|
| 1. Inventory | Map how invoices flow today: outgoing (which system creates them, in what format) and incoming (which channels, who processes them) |
| 2. Systems check | Confirm what your ERP/invoicing tool and your accounting setup can already do — most modern systems, including the DATEV stack, support XRechnung and ZUGFeRD; the gap is usually configuration, not software |
| 3. Format decision | Choose the issuing format(s) per customer group; agree the reception channel and validation step |
| 4. Process rewiring | Connect reception to the accounting workflow — data in, not PDFs retyped; set up compliant archiving of the structured originals |
| 5. Test and switch | Run real invoices with a friendly customer and supplier; fix the mapping issues while they're cheap; then switch before the deadline, not on it |
For a typical small or mid-sized company this is a few weeks of focused work — not a year-long transformation. The companies that suffer are the ones that compress those weeks into the last month of 2026.
DATEV and your invoicing stack
For the majority of German companies whose accounting runs through DATEV, the good news is that the tooling is largely in place: the DATEV ecosystem creates, sends, receives and processes e-invoices in the current XRechnung and ZUGFeRD standards. The work sits in the connections — making sure your invoicing tool, the DATEV environment and the tax advisor hand-off speak the same structured language, the same alignment discipline covered in our DATEV setup guide. If your chart of accounts and advisor mappings are clean, adding the e-invoice layer is configuration. If they aren't, this is the deadline that finally forces the cleanup.
Where an interim controller fits in
The e-invoicing transition is a textbook scoped mandate: a defined outcome, a hard external deadline, work that cuts across systems, process and the tax-advisor relationship — and no need for a permanent hire at the end of it. It's the same shape as the projects covered across this blog: an interim controller runs the inventory, makes the format and process decisions with the stakeholders, wires reception into the month-end close so structured invoices actually speed up the close instead of adding a parallel channel, and hands over a running, documented process. Done early, it's unglamorous plumbing. Done late, it's an emergency with an immovable date.
Conclusion
German e-invoicing is not a future topic — reception has been mandatory for every company since 2025, the issuing mandate lands on 1 January 2027 for everyone above €800,000, and covers all companies a year later. Only structured formats count, and the PDF most companies rely on isn't one. The whole transition is a few weeks of well-organised work with cheap mistakes if started now — and expensive ones if started in December. The deadline won't move. The only variable is how calm the run-up is.
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Frequently asked questions (FAQ)
When does e-invoicing become mandatory in Germany?
Reception of structured e-invoices has been mandatory for every German company since 1 January 2025, with no transition period. Issuing becomes mandatory for domestic B2B invoices from 1 January 2027 for companies above €800,000 prior-year revenue, and from 1 January 2028 for all companies.
Is a PDF invoice an e-invoice under the German rules?
No. An e-invoice must contain structured, machine-readable XML data that systems can process automatically. A plain PDF is unstructured — a picture of an invoice, not data — and does not meet the requirements, however digitally it's delivered.
What is the difference between XRechnung and ZUGFeRD?
XRechnung is a pure XML format with no visual layer, standard in public-sector invoicing. ZUGFeRD is a hybrid: a readable PDF with the structured XML embedded inside, so humans see a familiar document while systems process the data. Both satisfy the German requirements.
What happens if I receive or issue non-compliant invoices?
The main financial exposure sits on the receiving side: where an e-invoice is required, a non-compliant document is strictly not a proper invoice, which can put VAT input deduction at risk and cause delays and corrections. The specific tax consequences for your situation are a question for your tax advisor.
How long does the e-invoicing transition take for an SME?
Typically a few weeks of focused work: inventorying invoice flows, checking system capabilities, choosing formats, rewiring reception into the accounting workflow with compliant archiving, and testing with real counterparties. Most modern systems including the DATEV stack already support the formats — the work is configuration and process, not new software.