Software choice
German e-invoice software: which solution you actually need
Short answer: there are two kinds of “e-invoice software”. One is a full accounting or ERP suite with a UI, customer management and delivery. The other is a focused e-invoice engine that turns your existing data into a technically valid EN 16931 file and checks it. fakturai is the second kind — narrow, embeddable and with a KoSIT-aligned accept gate. Which one you need depends on what your current software already produces.
Two kinds of e-invoice software
- Accounting / ERP suite. Creates invoices in its own UI, manages customers and records, and increasingly emits e-invoices too. Sensible if you want a complete bookkeeping system in one tool.
- Focused e-invoice engine / API. Does one thing: turns your data into an EN 16931-compliant ZUGFeRD/Factur-X or XRechnung file — via REST API or MCP server, in seconds, with technical validation. Sensible when your data already lives in a shop, CRM, ERP or in-house system and you only need compliant e-invoices out of it.
When is your existing software enough — and when not?
Before buying new software, check what your current system already outputs. You need no extra tool if it already produces a structured XML part per EN 16931 in a compliant profile. You need a complementary e-invoice engine if:
- your system only outputs a PDF — a plain PDF is not an e-invoice;
- you want to generate e-invoices from your own systems, shops or workflows without switching accounting tools;
- you generate e-invoices automatically or via agents (API, MCP, n8n, Make, Zapier);
- you want to validate incoming or self-generated files technically before they are sent.
E-invoice software without a full accounting system
That is exactly what fakturai is built for: add a seller profile, get an API key and generate EN 16931-compliant ZUGFeRD/Factur-X invoices via the REST API or the MCP server. Every generated file passes the same KoSIT-aligned accept gate as the free validator — the technical bar is the same everywhere. You keep your existing system; fakturai only takes the part that truly has to be compliant.
Validate an e-invoice for free · Create an API key and start free · Create e-invoices via API & MCP
What to look for in e-invoice software
A nice UI says nothing about compliance. Check the output:
- does it produce a structured XML part per EN 16931 — not just a PDF image?
- are XRechnung and ZUGFeRD/Factur-X supported in a compliant profile (e.g. EN 16931 / COMFORT, not MINIMUM)?
- is there real technical validation with a KoSIT-aligned accept gate — before sending?
- can generation be integrated into your existing systems (API, MCP, automation)?
The first three are answered in seconds by the free fakturai validator, for any file regardless of which software made it. See the validation checklist and why a PDF is not an e-invoice.
What fakturai is — and is not
- What it is: a focused tool that generates and technically validates EN 16931-compliant e-invoices — via API, MCP and a free validator, with a KoSIT-aligned accept gate.
- What it is not: not an accounting or ERP suite, not a replacement for DATEV or your tax advisor, no customer management or dunning. That focus is exactly what makes it easy to integrate and the output easy to verify.
What fakturai does not replace (GHOA-1671)
fakturai checks and generates technical format and structural compliance per EN 16931 with a KoSIT-aligned accept gate. The substantive and tax correctness of the invoice, bookkeeping, retention duties and delivery remain your responsibility (or your tax advisor’s). fakturai is not tax advice and makes no legal, tax or delivery guarantees.
Next step
Free German e-invoice validator
Related: Create e-invoices · What is actually free · E-invoices and DATEV · For tax advisors · Small business guide