Upload, official rules, clear errors. The file stays in request memory only.
E-invoice check · KoSIT rules
Upload the e-invoice. See the errors.
To check whether an XRechnung or ZUGFeRD invoice is valid, upload it here for free. It is validated against the 1646 rules in the KoSIT validator configuration of 2026-08-31 (EN 16931 1.3.16, XRechnung 3.0.2), and each error is shown with its rule code and an explanation.
Free check against current KoSIT / EN 16931 / XRechnung rules. Human-readable errors. For recurring checks: API / Batch preflight from €79/mo.
Files are ephemeral · not stored
KoSIT 1.6.3 · XRechnung 3.0.2 · EN 16931 1.3.16
What you get
German fix hints — not raw Schematron only.
Recurring preflight before send — waitlist from €79/mo.
No Peppol access point, no invoice editor, no portal submit, no AI as source of truth.
Supported / not supported
| Item | Status |
|---|---|
| XRechnung UBL | yes |
| XRechnung CII | yes |
| ZUGFeRD PDF with embedded XML | yes |
| Plain PDF without XML | not-an-e-invoice message |
| File size | max. 5 MB |
| Rule versions | KoSIT 1.6.3 · XRechnung 3.0.2 · EN 16931 1.3.16 |
| Files stored | not stored |
| Login | no |
| Peppol or portal submit | no |
| Creating invoices | no |
| Bank / portal overlays | no |
Questions
In short: validity is decided only by the official KoSIT rules (1646 rules, configuration 2026-08-31), not by AI.
Which formats?
XRechnung XML (UBL and CII), and a ZUGFeRD PDF when an XML is embedded. A PDF without XML gets the not-an-e-invoice message.
Is my file stored?
No. The file is processed only in request memory. It is not written to disk, not logged as XML, and not sent to a language model (persisted: false).
Does “valid” mean ZRE/OZG-RE will accept it?
No. A file can pass here and still be rejected by ZRE, OZG-RE or another portal. Portal and bank overlays are not checked.
Is there an API?
Yes. POST /v1/validate is free, up to 50 validations per IP per UTC day. Batch and higher volume stay on a waitlist from €79/month. Joining is free; you are charged only after confirmation. API docs
What does it cost?
The browser check and POST /v1/validate are free (50 per IP per UTC day). Batch and higher volume are planned from €79/month. Joining the waitlist is free; you are charged only after confirmation.
Which rule version?
KoSIT validator 1.6.3, XRechnung 3.0.2, EN 16931 Schematron 1.3.16. The configuration release is 2026-08-31 (scenarios.xml dated 2026-09-02).
API / Batch · from €79/mo
Check e-invoices regularly?
API / batch check / preflight before send — from €79/mo. Waitlist is free; we’ll confirm before any charge.
Planned (waitlist)
- API or batch validation against current KoSIT / XRechnung rules
- Preflight before portal / bank send
- Email reply for onboarding
Not included (now)
- Batch and higher volume — waitlist only
- One-shot repair of a single file
- Payment on this page