Small Businesses (§ 19 UStG) & E-Invoicing: Receiving vs. Issuing

Small businesses (Kleinunternehmer under § 19 UStG) get two very different answers to the e-invoicing question depending on the direction. On receiving, they are treated exactly like everyone else. On issuing, they enjoy a permanent exemption that larger companies do not. Confusing the two directions is the single most common mistake, so this article separates them cleanly.

> Short answer: Kleinunternehmer must receive e-invoices like everyone else since 1 January 2025. They are permanently exempt from issuing them — they may always send a plain PDF or paper 'sonstige Rechnung' — under the JStG 2024, anchored in § 34a UStDV (BMF letter of 18 March 2025). They may issue voluntarily with the recipient's consent.

Receiving: no exemption

The receiving obligation applies to all domestic businesses from 1 January 2025, and it makes no exception for small businesses. If a supplier sends you a ZUGFeRD or XRechnung file, you must be able to accept and store it.

In practice this means:

• You need a mailbox and a way to open structured e-invoices (any viewer or accounting tool will do).
• You must archive the original structured XML unaltered and audit-proof for 8 years under GoBD.
• You cannot refuse an e-invoice on the grounds that you are a small business — there is no such exemption for receiving.

This is the part small businesses most often overlook, because it feels like the mandate "does not apply to them." It does, for receiving.

Issuing: a permanent exemption

Here the picture flips. Kleinunternehmer are permanently exempt from the obligation to issue e-invoices. They may always issue a "sonstige Rechnung" — an ordinary invoice in PDF or paper form — instead of a structured e-invoice.

The legal basis:

• Introduced by the JStG 2024 (Annual Tax Act 2024)
• Anchored in § 34a UStDV
• Confirmed by the BMF letter of 18 March 2025

"Permanently" is the operative word. Unlike the general 2027/2028 sending mandate that phases in for other businesses, this exemption is not a temporary transition period. A Kleinunternehmer never *has* to issue an e-invoice.

The two directions side by side

Voluntary issuing is allowed

The exemption is a right, not a prohibition. A small business may issue an e-invoice voluntarily — for example because a business customer prefers structured data for their bookkeeping. The one condition is recipient consent: you cannot force a structured e-invoice on a customer who does not want one, and they cannot force one on you.

So the choice is genuinely yours:

• Keep sending PDFs? Fully compliant.
• Send ZUGFeRD because a customer asked? Allowed, with their consent.

What this means practically

For a typical Kleinunternehmer the sensible setup is:

1. Sort out receiving now. Make sure you can open and archive incoming e-invoices. This is the only hard obligation, and it is already in force.
2. Keep issuing PDFs unless a customer specifically wants an e-invoice.
3. Convert on request. If a customer does want structured data, convert your existing PDF rather than adopting new invoicing software.

The receiving edge case: a supplier who sends a PDF

Ironically, the friction often comes the other way: a supplier who is *not* a small business sends you a plain PDF instead of a proper e-invoice. That PDF is not a valid e-invoice under § 14 UStG, and you may want a structured version for clean bookkeeping and archiving. Converting it gives you a file you can archive and book like any other e-invoice.

Cover both directions without new software

You are exempt from *issuing* e-invoices — but you must *receive* them, and you may want to convert the occasional PDF, whether one a customer asked you for or one a supplier sent.

TaxLayer converts a PDF invoice into a validated ZUGFeRD or XRechnung file you can send on request or archive on receipt. The first two conversions each month are free — no credit card required.