Free E-Invoicing Software for Germany: Options Compared

Free e-invoicing software for Germany exists, but not as one tool that does everything. To receive e-invoices, an e-mail inbox and a free viewer are enough. To issue them from 2027, you need a tool that produces XRechnung or ZUGFeRD 2.0.1 or later. Which tool fits depends on five tasks: receiving, issuing, validating, archiving and exporting.

This guide does not rank vendors. It explains the criteria for judging a free e-invoicing solution, the categories that exist, what each covers, and where free plans usually stop. It is written for freelancers, founders and finance teams in Germany, and for foreign suppliers who need to know whether the German rules reach them at all.

Does the German mandate apply to you?

Before choosing software, check the scope. The obligation to issue e-invoices to other businesses under Section 14 of the German VAT Act (§ 14 UStG (opens in a new tab)) applies to supplies between businesses that are both established in Germany. A company without a German establishment that invoices a German customer is generally not caught by the B2B rule. The rules and deadlines are summarised in our guide to the Germany e-invoicing mandate.

Public-sector buyers follow separate rules. Suppliers to German federal authorities have had to submit electronic invoices since 27 November 2020 under § 3 of the federal e-invoicing ordinance (E-RechV), according to the federal e-invoicing FAQ (opens in a new tab).

What tasks must e-invoicing software cover?

The German mandate is several obligations with different legal bases. Not every business has all of them.

Software comparisons often skip two rows. A viewer that only displays a file does not meet the archiving duty. And while the law prescribes no validation tool, a broken file otherwise reaches your books unchecked. The details every German invoice must carry, whatever the format, are in German invoice requirements.

What categories of free e-invoicing solutions exist?

Free offers fall into four groups. "Partly" means it depends on the individual product, so read the vendor's own description.

Government services

The German tax administration offers an e-invoice viewer at e-rechnung.elster.de that displays XRechnung files without logging in. It is a reader. It does not create, validate or store invoices.

For invoices to the federal administration there is the federal invoice portal OZG-RE. Its FAQ states that registration and use are free for invoice senders. With manual web entry (Weberfassung) (opens in a new tab), you type the invoice data into the portal after registering, and the portal produces the e-invoice. The federal site recommends this route for suppliers without their own e-invoicing software or with few invoices. It does not help with invoices to companies: the OZG-RE only delivers to connected public-sector recipients.

Online tools

Web tools usually cover one task well: create an invoice, display an XRechnung, or pull the XML out of a ZUGFeRD PDF. Many work without an account and suit low volumes. Check whether your file stays in the browser or is uploaded to a server; the provider's privacy policy should say so.

Free plans of invoicing software

When an invoicing or accounting product offers a free plan, it is normally limited by volume or features. Whether it includes XRechnung, ZUGFeRD or both, whether there is an inbound channel, and whether it archives, is only reliable from the vendor's own documentation. For a product you already use, start with its help pages. Our guide to DATEV e-invoices shows what that looks like for one widely used German system.

Open-source software

Three open-source projects are common in German e-invoicing, all under the Apache License 2.0:

• KoSIT validator: the validation engine of the German Coordination Office for IT Standards (KoSIT). It runs as a Java command-line tool or as an HTTP service in daemon mode and needs a validation configuration, such as the XRechnung one. See our guide to the KoSIT validator.
• Mustangproject: a Java library for ZUGFeRD invoices that developers embed in their own applications.
• Quba viewer: a cross-platform desktop application that, according to the project, displays structured (XML) and hybrid (Factur-X/ZUGFeRD PDF) invoices.

Open source has no licence fee, but it needs installation and, for KoSIT and Mustang, a Java runtime. For an office without IT support that is real work.

What do you need to receive e-invoices?

Since 1 January 2025, businesses established in Germany must be able to receive e-invoices. There is no transition period for receiving (BMF letter of 15 October 2024, para. 62). The minimum setup costs nothing:

1. An e-mail address you give your suppliers. A separate inbox is not required (para. 40).
2. A viewer to read XRechnung files. ZUGFeRD invoices open as PDFs, but the embedded XML is the leading part.
3. A storage location where the original XML stays unchanged, separate from printouts and PDF renderings.
4. Optionally, a validation step before you pay or book.

Step 3 is the one people get wrong. A folder on a shared drive is not automatically unalterable. What the German bookkeeping principles (GoBD) require is covered in e-invoice archiving in Germany.

What do you need to issue e-invoices from 2027?

Businesses whose total turnover in 2026 exceeded EUR 800,000 must issue e-invoices to German business customers from 1 January 2027; everyone else must do so by 2028 at the latest. The details are in Germany e-invoicing 2027. Small businesses under § 19 UStG are exempt from issuing, not from receiving.

What matters is the output file, not the brand of software. A Word or Excel PDF does not become an e-invoice by renaming it; the routes that work are in convert a PDF to an e-invoice. For a handful of invoices a month, an online generator is enough. Once you send dozens a month, a tool that manages customers, items and invoice numbers pays off.

Where do free plans stop?

Free plans are legitimate, but they have edges. Use this checklist when reading a provider's terms, before you enter your data.

The archive row deserves the most attention. If a free plan ends or a service shuts down, you must still be able to produce your e-invoices for the whole retention period. Keep a copy of every XML you send and receive in your own storage.

Which option fits which situation?

How to issue, validate and read e-invoices with docutools.pro

docutools.pro is not accounting software and is not an archive. Its tools cover three of the five tasks and complement other software:

1. Issue: in the XRechnung generator, fill in invoice number, date, seller and buyer under "Company", plus "Buyer reference / Leitweg-ID" for public-sector buyers. Add lines and the VAT rate under "Items". Under "Export", choose "XRechnung XML", "ZUGFeRD XML" or "ZUGFeRD PDF". Single invoices work without an account (fair-use limit). The generator cannot create credit notes or corrections and has no small-business option.
2. Get the XML out of a ZUGFeRD PDF: in the ZUGFeRD XML extractor, click "Choose PDF", then "Download XML". This runs in your browser; the PDF does not leave your computer.
3. Validate and read: upload the XML to the XRechnung validator. The file is sent to our server for the check. The "KoSIT validation" checks the way the KoSIT validator does (configuration 2026-08-31) and shows "KoSIT-conformant / Valid XRechnung" or "Not KoSIT-conformant" with the rule violations.
4. Use the result: the extracted data table lists invoice number, parties, VAT IDs, totals and line items. It does not show the Leitweg-ID, IBAN or due date.
5. Archive: save the original XML in your own archive. The searchable history in the viewer ("GoBD Vault") is a Pro feature.

The free viewer allows 2 uploads a day of up to 500 KB each. Unlimited checks, batch processing and CSV export are part of the Pro plan. More guides are collected under invoicing in Germany.

Sources

• § 14 UStG (opens in a new tab) and § 14b UStG (opens in a new tab) on Gesetze im Internet
• Federal Ministry of Finance: BMF letter of 15 October 2024, BStBl I p. 1320, paras. 28, 30, 37, 40, 60, 62, and the BMF letter of 15 October 2025 (opens in a new tab)
• E-Rechnung des Bundes: OZG-RE FAQ (opens in a new tab) and manual web entry (opens in a new tab)
• KoSIT: KoSIT validator on GitHub (opens in a new tab)
• Mustangproject (opens in a new tab) and Quba viewer (opens in a new tab) on GitHub

Last reviewed: October 2026

This article is general information, not tax or legal advice.