Limited availability
Founding Pilot Program
We're working with a small number of developers, engineering teams, and integration partners to validate production use cases across EU e-invoicing formats.
Free Pro access. Direct line to the team. No commitment.
What you get
Everything you need to evaluate and integrate. No sales calls required.
Pro for free
Full Pro access — 10,000 invoices/month, batch processing, auto-fix, webhooks, and signed evidence packs. No credit card required.
API keys in 5 minutes
Live and sandbox keys. Full API documentation. Start sending invoices the same day.
Direct line to the team
Dedicated Slack channel with the founding team. Weekly 15-minute check-ins. 24-hour bug fix SLA.
Roadmap input
Your use cases shape the product. Country-specific rules, format support, integration patterns — built with you.
Product
How the engine works
XML invoice in via API. Corrected, KoSIT-revalidated XML out. With a signed evidence pack per invoice and human-readable explanations for anything that can't be auto-fixed.
Structural XML errors, namespace declarations, element ordering, date formatting, code normalization via official UN/ISO mapping tables, derivable default values.
Engine knows the answer but the field is sensitive. Example: deriving an EndpointID scheme from a VAT number pattern. The engine proposes, you confirm.
Engine doesn't have the answer. Example: a missing Leitweg-ID for German B2G invoices, or a buyer endpoint not present in the invoice.
Financial totals, amounts, IBAN/BIC. The engine refuses to modify these and explains why, with documentation links and vendor messaging templates.
Hybrid pipeline with KoSIT revalidation
Not self-assessing. The same authoritative validator (KoSIT, used by the German government) validates both input and output. What comes out of the fixer is externally verified.
Four safety guarantees
Financial fields are never touched. Every fix requires evidence. Every modification is simulated before applied. Full rollback on any invariant violation.
Denylist
Financial fields, payment identifiers, VAT numbers, invoice references — hardcoded, never touched.
High-Risk Gate
3D routing matrix: field type x modification type x evidence level. Not binary blocking — contextual routing.
Evidence System
Every fix requires formal evidence. PROOF needs pattern validation + corroboration. No evidence = no fix.
Invariant Checks
Post-fix snapshot comparison. If error count increased, critical errors grew, or severity elevated — full rollback.
Full security architecture and data handling: invoicenavigator.eu/trust
Supported formats
Format detection is automatic based on CustomizationID and namespace.
Country-specific rules
27 EU member states covered. 1,300+ validation rules. Automatic ruleset updates.
Evidence packs — audit-ready compliance proof
Every processed invoice produces a cryptographically signed evidence pack. Not a report — a verifiable certificate. RSA SHA256 signature, public key at /.well-known/evidence-pack-keys.
Publicly verifiable
Every pack has a URL anyone can open — your customers, their accountant, an auditor. No login required.
Batch support
Multiple invoices in one certificate. Pass/fail per invoice. One signed pack for the batch.
PDF or JSON
PDF for accountants and auditors. JSON for integration into your system. Both cryptographically signed.
Integration
One endpoint. Under one sprint.
Send an XML invoice, get a corrected XML back. The response tells you exactly what was fixed, what needs your input, and what was blocked — with full safety reports.
POST /api/v2/validate-and-fix
Content-Type: application/json
Authorization: Bearer sk_live_xxx
{
"xml": "<Invoice>...your XML...</Invoice>",
"fix_policy": "safe",
"generate_evidence_pack": true
}
Response:
{
"success": true,
"data": {
"validationRef": "val_8B9319",
"originalValid": false,
"fixedValid": true,
"fixesApplied": 8,
"fixedXml": "...corrected invoice...",
"remainingIssues": [],
"fixSummary": {
"totalIssues": 12,
"autoFixable": 8,
"needsInput": 2,
"blocked": 2
},
"metadata": {
"invoiceNumber": "INV-2026-001",
"format": "xrechnung-ubl",
"sellerCountry": "DE",
"buyerCountry": "NL"
}
}
}Who this is for
We're looking for developers and engineering teams with a real e-invoicing pipeline and a production use case. Not testing curiosity — real invoices, real pain.
What we ask
This is not the Free tier with no expectations. We want structured feedback from serious early adopters.
50 real invoices minimum
Not synthetic. Real production data through the engine.
Honest feedback
Which fixes are correct. Which aren't. What's missing.
30-minute retrospective
At the end of the pilot. What worked, what didn't, what's next.
We do not ask for payment, commitment to become a customer, marketing permissions, or case study rights.
How the pilot works
From application to results in weeks, not months.
Apply
Fill out the form below. Instant approval — no waiting.
Create account
Click the link in your email to create your account. Takes 30 seconds.
Pro activated
Your account is automatically upgraded to Pro. Full access from day one.
Integrate
Start sending invoices through the engine. API keys are ready on signup.
Need to share this with your team?
Download the full pilot program spec as PDF. Product architecture, safety system, integration guide, pilot terms — everything a tech lead or developer needs to evaluate.
Apply for the Founding Pilot Program
Instant approval. Create your account to activate Pro.