Why this matters
Domestic businesses have had to be able to receive e-invoices since 1 January 2025, including businesses using the Kleinunternehmer VAT exemption. Transition periods for issuing run until the end of 2026 or, for issuers with prior-year turnover not exceeding €800,000, until the end of 2027. A business storing only PDFs may be confusing a human-readable view with the legally relevant structured record.
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Create start planWhat an e-invoice actually is
An e-invoice is not just any electronic invoice. It must be issued, transmitted, and received in a structured electronic format that supports electronic processing and generally complies with the European EN 16931 standard.
Common German formats include XRechnung as an XML file and a compliant ZUGFeRD profile combining a PDF view with embedded structured data. A normal PDF, scan, or photograph is a different type of invoice and is not automatically an e-invoice.
The structured part is decisive. A PDF preview helps people read the invoice, but your bookkeeping and retention process must not keep only the image while discarding the original data.
You have had to receive e-invoices since 2025
Domestic businesses have had to support receipt since 1 January 2025. The Federal Ministry of Finance FAQ provides no general exception, including for businesses using the Kleinunternehmer VAT exemption. An email inbox is generally sufficient as the technical transmission route.
In practice, you need more than an address. Define which inbox suppliers use, who safely opens XML files, how malware and payment-fraud risks are checked, and how receipt, approval, payment, and filing connect.
You do not need an expensive portal for every small operation. A controlled process with a secure viewer and organised storage can work for low volume. As the volume grows, bookkeeping software that imports and preserves structured data becomes more useful.
Which transactions the duty is designed for
Mandatory e-invoicing generally concerns invoices for transactions between domestic businesses. Private consumers are not the target case. B2G invoices for public-sector customers also have their own requirements and should not be equated with the B2B transition rules.
Exceptions include certain VAT-exempt transactions, low-value invoices up to €250, and transport tickets. Since 2025, supplies by businesses using the Kleinunternehmer VAT exemption are also exempt from the duty to issue an e-invoice, while the duty to receive remains.
Cross-border supplies, reverse charge, self-billing, and other special cases need their own tax assessment. An XML file by itself does not establish that an invoice is correct for VAT purposes.
The transition periods through 2028
Until 31 December 2026, all issuers may continue to use another invoice type for covered transactions. Paper remains possible; another electronic format such as a simple PDF generally requires the recipient's consent.
Where the issuer's total turnover in the preceding calendar year did not exceed €800,000, that transition generally continues until 31 December 2027. Certain EDI arrangements can also continue until the end of 2027.
From 2028, structured domestic B2B e-invoicing becomes the standard outside statutory exceptions. Under current law, Kleinunternehmer remain exempt from issuing, although voluntarily supporting a structured format may help when customers request it.
Review, approval, and unchanged retention
Continue checking the sender, supply, amount, tax details, and bank account on every e-invoice. Structured data does not prevent a forged supplier email or a manipulated payment destination.
The original structured component must be retained so that it remains unchanged and machine-readable. Printing the XML or keeping only a generated PDF view is not enough. Transformations, corrections, and approvals should remain traceable.
Connect the e-invoice to the order, evidence of supply, and payment. It then becomes a controlled bookkeeping record rather than a file that was merely received.
A lean setup for a side business
Create a fixed invoicing address and tell your business partners about it. Test at least one XRechnung and one ZUGFeRD file before a real payment deadline starts. Record the viewer, storage location, file naming, review, and backup process.
Ask your invoicing provider which EN 16931-compliant formats and profiles it exports, whether it validates the structured data, and how corrections work. A vague ‘e-invoice ready’ promise is not enough.
Align the process with your tax adviser or bookkeeping handover. This avoids duplicate data entry and the year-end discovery that only preview images, not original files, were retained.
Quick checklist
- Set up a fixed business address for receiving invoices.
- Define who opens, validates, approves, pays, and files invoices.
- Test a secure viewer for XRechnung and ZUGFeRD.
- Run at least one test file from receipt through retention.
- Do not confuse Kleinunternehmer status with an exemption from receiving.
- Classify your own B2B, B2C, B2G, and cross-border invoices separately.
- Document prior-year turnover and the applicable issuing deadline.
- Retain the original structured data unchanged.
- Verify changed bank details through a second channel.
- Check the tool export and handover to bookkeeping or your tax adviser.
Common mistakes
- Calling every PDF invoice an e-invoice.
- Failing to provide a receipt route because you use the Kleinunternehmer exemption.
- Applying the €800,000 threshold to the recipient instead of the issuer.
- Putting B2C and B2G invoices into the same transition analysis without checking.
- Keeping only the visual PDF view instead of the original structured record.
- Opening XML attachments carelessly or immediately accepting changed bank details.
- Waiting until the end of 2027 without testing the tool, customer requirements, and handover.
Frequently asked questions
Do I need e-invoicing as a Kleinunternehmer?
You must be able to receive e-invoices. Under current law, businesses using the Kleinunternehmer VAT exemption are exempt from the duty to issue one, although customers may still request a structured format voluntarily.
Is a normal email address enough for receipt?
An email inbox can be sufficient as the legal transmission route. Operationally, you also need a secure way to read, check, approve, and retain the structured file unchanged.
Is every ZUGFeRD file a valid e-invoice?
Only suitable ZUGFeRD versions and profiles whose structured data meet the legal requirements qualify. A PDF with an arbitrary XML attachment or an unsuitable profile is not automatically sufficient.
What this guide can and cannot do
This guide helps with
- sort your invoice cases by receipt, issue, B2B, B2C, and transition period
- create a small process and tool checklist
- separate the concepts of PDF, XRechnung, ZUGFeRD, and structured data
This guide does not replace
- validate a specific invoice as legally or technically correct
- make a binding deadline assessment where turnover or a special case is unclear
- replace bookkeeping software, the tax office, or a tax adviser