E-invoice validation API

Validate XRechnung, ZUGFeRD / Factur-X and Peppol BIS 3.0 invoices from your code or CI pipeline with the same official rules as our online validator. One POST, a JSON answer, no API key.

Request

POST https://invoiceer.io/api/validate as multipart/form-data with the invoice in the field file. It accepts UBL or CII XML, or a ZUGFeRD / Factur-X PDF with embedded XML (up to 10 MB).

curl -F "[email protected]" https://invoiceer.io/api/validate

import httpx

with open("invoice.xml", "rb") as f:
    r = httpx.post("https://invoiceer.io/api/validate", files={"file": f}, timeout=60)
result = r.json()
if not result["valid"]:
    for e in result["errors"]:
        print(e["code"], e["text"])

Response

A valid invoice:

{"valid": true, "format": "Peppol BIS Billing 3.0 (UBL Invoice)", "source": "xml", "errors": [], "warnings": []}

An invalid one (amount due doesn't match the totals):

{
  "valid": false,
  "format": "Peppol BIS Billing 3.0 (UBL Invoice)",
  "source": "xml",
  "errors": [
    {
      "level": "error",
      "code": "BR-CO-16",
      "text": "[BR-CO-16]-Amount due for payment (BT-115) = Invoice total amount with VAT (BT-112) -Paid amount (BT-113) +Rounding amount (BT-114).",
      "location": "/Invoice[1]/LegalMonetaryTotal[1]"
    }
  ],
  "warnings": []
}

Field	Meaning
`valid`	`true` if no errors (warnings allowed).
`format`	Detected format, e.g. XRechnung (UBL or CII), Peppol BIS 3.0, EN 16931 CII / ZUGFeRD. `null` if not recognised.
`source`	`xml` or `pdf` (XML extracted from a ZUGFeRD / Factur-X PDF).
`errors`, `warnings`	Each with `level`, rule `code` (e.g. BR-CO-16, BR-DE-15, PEPPOL-EN16931-R001, or an XML schema error), `text` and `location` (XPath or line and column).

Every business rule has a plain-language explanation at https://invoiceer.io/rules/<code>, for example /rules/BR-CO-16. Link your users there.

Errors in the request itself (empty file, not XML, a PDF without embedded XML, XML with a DOCTYPE) return HTTP 400 with {"error": "..."}.

Rules used

XRechnung: the official KoSIT validator with the XRechnung configuration (UBL and CII).
Peppol BIS Billing 3.0: OpenPeppol schematron, including EN 16931.
EN 16931 (CEN) for UBL and CII, which covers ZUGFeRD / Factur-X EN 16931 profiles.

Limits and privacy

Free, no sign-up. Fair use: 40 checks per hour per IP address. Above that you get HTTP 429.
Files are processed in memory and discarded immediately. We don't store invoices or results.
Provided as is, without guarantees. For production volumes or an SLA, email [email protected].

Creating e-invoices from Stripe

If you bill with Stripe, you don't need to generate and validate e-invoices yourself: Invoiceer for Stripe turns every Stripe invoice into a validated XRechnung, ZUGFeRD or Peppol invoice automatically.