The library is free forever. Plans buy certainty.
Unlimited local validation with the open-source library, always. Paid plans sell what code alone can't promise: always-current rules without upgrades, volume, client-project leverage, and platform compliance posture.
- ✓100 hosted API calls / month
- ✓Unlimited local validation (open-source library)
- ✓XRechnung validation + generation
- ✓Playground with AI explanations
- ✓Community support
- ✓5,000 documents / month
- ✓Always-current rules — no dependency upgrades
- ✓Version-pinned validation results
- ✓Email support
- ✓25,000 documents / month
- ✓Unlimited client projects
- ✓White-label validation reports (coming)
- ✓Priority support
- ✓Early access to new formats (Factur-X, Peppol BIS)
- ✓100,000 documents / month, usage-based beyond
- ✓DPA/AVV + EU data residency (rolling out)
- ✓Rule-update SLA: new KoSIT releases within days
- ✓Version pinning per integration
- ✓Direct line to the team
Frequently asked questions
What counts as a document?
Each request to /api/v1/validate or /api/v1/generate counts as one document. Local validation with the open-source @stampbench/core library is unlimited and free forever — the quota only applies to the hosted API.
What does the Platform tier actually include?
Usage-based pricing beyond 100k documents, a signable DPA/AVV and EU data residency (rolling out), version pinning per integration, and a rule-update commitment: new KoSIT releases supported within days, contractually.
Why pay when the library is free?
The hosted API gives you always-current rule sets without dependency upgrades, AI-written error explanations, usage across any language (not just Node.js), team-visible history, and someone else maintaining the Schematron treadmill as XRechnung versions change.
Do you support Factur-X / ZUGFeRD, Peppol BIS, or FatturaPA?
Validation supports both syntaxes today, auto-detected: UBL and CII (the ZUGFeRD/Factur-X XML most German invoices arrive as). Generation is XRechnung UBL. Factur-X PDF generation, Peppol BIS and FatturaPA are next — Agency subscribers get early access.
Is this legal advice? Will my invoice be accepted?
Stampbench is developer tooling, not legal advice. We implement the published EN 16931 and XRechnung rules and document our coverage precisely; for certification-grade sign-off, also run the official KoSIT validator (we make passing it much easier).
Can I cancel anytime?
Yes — plans are monthly, cancel in one click from the billing portal, and your plan simply drops to Free at the end of the period.
What about annual billing or EUR pricing?
Both are coming. Email us and we will set you up manually in the meantime.