The Command "validate"

Validating both incoming and outgoing invoices is a crucial part of electronic invoice processing that ultimately saves time and money. Many e-invoicing systems automatically validate documents and reject those that fail to meet the required standards. This can lead to unnecessary delays, disrupt business processes, and potentially harm customer relationships.

Voraussetzungen

All known e-invoice validation software is written in Java. Before you can use the validate command, you have to make sure that a Java Runtime Environment is installed on your system.

Java Runtime Enviroment (JRE)

Many systems will have a Java Runtime Environment pre-installed. You can test that by typing java -version into a commandline terminal. If there is no command java or the reported version is less than 11, you have to install a Java Runtime Environment. In doubt, you can download the OpenJDK version which is available for all operating systems and Microsoft Windows.

E-Invoice-EU-Validator

The available offline validators are written in Java which has the effect that they have a considerably high start-up time. This is also true for the MustangProject validator, the only offline validator capable of validating all supported formats. This is unfortunate because the MustangProject can validate only one document at a time so that this start-up penalty has to be paid for every document validated.

The sister project e-invoice-eu-validator jumps into this gap by providing a simple server that uses the MustangProject library.

Installation

Download a file validator-VERSION-jar-with-dependencies.jar from the E-Invoice-EU Validator releases page. Save the file at a location of your choice.

Start the Validation Server

This command starts the server:

java -jar validator-VERSION-jar-with-dependencies.jar

This will start the server listening on port 8080. If you want to use another port, pass it in the environment variable PORT.

Validate Documents

You can now validate an arbitrary number of invoice documents:

e-invoice-eu validate invoice*.xml invoice*.pdf

The output looks like this:

invoice-283784.xml: ✓ valid
invoice-445937.pdf: ✓ valid
invoice-459872.xml: ✗ invalid
invoice.xml: ✗ invalid
<?xml version="1.0" encoding="UTF-8"?>

<validation filename="invoice.xml" datetime="2025-04-26 09:01:12">
  <xml>
    <messages>
      <error type="18">schema validation fails:org.xml.sax.SAXParseException; lineNumber: 305; columnNumber: 62; cvc-datatype-valid.1.2.1: 'tons of money' is not a valid value for 'decimal'.</error> 
    </messages>
    <summary status="invalid"/>
  </xml>
  <messages></messages>
  <summary status="invalid"/>
</validation>

invoice-845937.pdf: ✓ valid

3 invoices valid.
One invoice invalid.

For invalid invoices, a detailed validation report is printed to the console.

If all invoices were valid, the program terminates with an exit code of 0. If at least one invoice was valid, it terminates with a non-zero exit code.

Options

The command validate supports the following options: