---
title: "Validation"
description: "Validating a UBL document's XML against the official OASIS UBL 2.1 XSD"
type: "docs"
category: "doc"
tags: []
authors: [Anonymous]
date: "2026-10-12"
last_update: "2026-10-12"
time_minutes: 2
draft: false
unlisted: false
url: "https://www.derafu.dev/docs/data/ubl/validation"
---

# Validation

`SchemaValidator` validates a document's XML directly against the official OASIS UBL 2.1 XSD
bundled with the package - the same schema real UBL consumers (Peppol Access Points, tax
authorities) validate against.

## Validating a Document

```php
use Derafu\Ubl\Service\SchemaValidator;

$validator = new SchemaValidator();

$validator->validate($xml); // Throws Derafu\Ubl\Exception\ValidationException if invalid.
```

Nothing is returned on success: a document either validates, or the call throws.

## Resolving the Document Type

Which XSD file to validate against is resolved automatically from the XML's own root element,
the same way `Deserializer` resolves a target class for `xml` (see Self-Describing Content in
**Formats**). An explicit class can be passed as a second argument to skip or override that:

```php
use Derafu\Ubl\Oasis\Doc\Quotation;

$validator->validate($xml, Quotation::class);
```

## Handling Validation Errors

A failed validation throws `Derafu\Ubl\Exception\ValidationException`, which exposes the real
list of `LibXMLError` objects libxml reported, not only a flat message:

```php
use Derafu\Ubl\Exception\ValidationException;

try {
    $validator->validate($xml);
} catch (ValidationException $e) {
    foreach ($e->getErrors() as $error) {
        printf("Line %d: %s\n", $error->line, trim($error->message));
    }
}
```

A malformed XML string, or a well-formed one whose root element matches no known UBL
document, also throws `ValidationException` - with `getErrors()` empty in both cases, since
neither one ever reaches schema validation itself: the document type could not be resolved to
begin with.



---
Last updated on 12/10/2026