Validation

Validate invoices before sending to catch errors instantly — no network call needed.

Client-side Validation

The SDK includes a built-in validator that checks your invoice against Peppol BIS 3.0 business rules before making any API call. This catches errors instantly and saves you a round-trip to the server.

How It Works

Call peppol.validate() with the same payload you'd pass to peppol.invoices.send(). The method returns a result object with valid, errors[], and warnings[].

Errors vs Warnings

  • Errors — blocking issues that prevent sending. Must be fixed.
  • Warnings — non-blocking suggestions for better compliance. Sending still works.
Validation is also run automatically when you call send(). If validation fails, a PeppolValidationError is thrown — see Error Handling. 
import { Peppol } from "@getpeppr/sdk";

const peppol = new Peppol({ apiKey: "sk_sandbox_..." });

// Validate locally before sending — catches errors instantly
const result = peppol.validate({
  number: "INV-2026-042",
  from: { name: "Acme BVBA", peppolId: "0208:BE0456789012", country: "BE" },
  to:   { name: "Globex NV", peppolId: "0208:BE0987654321", street: "Rue de la Loi 200", city: "Brussels", postalCode: "1000", country: "BE" },
  lines: [
    { description: "Consulting Q1", quantity: 40, unitPrice: 125, vatRate: 21 },
  ],
});

if (!result.valid) {
  for (const error of result.errors) {
    console.error(`[${error.field}] ${error.message}`);
    // e.g. "[from.vatNumber] VAT number recommended for invoices > EUR 400"

    if (error.suggestion) {
      console.log(`  Tip: ${error.suggestion}`);
      // "Add vatNumber to the seller party"
    }
  }
}

// Also returns warnings for non-blocking suggestions
for (const warning of result.warnings) {
  console.warn(`[${warning.field}] ${warning.message}`);
}

Response Format

The validation result contains structured error and warning objects with field paths that point to the exact location of each issue.

Error Object

  • field — dot-notation path (e.g. from.vatNumber, lines[0].unitPrice)
  • message — human-readable description of the issue
  • suggestion — optional fix recommendation
Use the field path to highlight specific form fields in your UI, giving users precise feedback on what to fix.
Validation Result 
{
  "valid": false,
  "errors": [
    {
      "field": "from.vatNumber",
      "message": "VAT number recommended for invoices > EUR 400",
      "suggestion": "Add vatNumber to the seller party"
    }
  ],
  "warnings": [
    {
      "field": "paymentIban",
      "message": "IBAN recommended for faster payment processing"
    }
  ]
}
Receiving Invoices
Document Status