How to check for a valid VAT Identification Number

If you sell in the European Union and are registered for VAT then you have to ask your clients for the VAT identification number (VATIN) before issuing an invoice. It is a good idea to make sure the VATIN is valid when generating the invoice otherwise you will have issues with your local tax authority.

Validation can be done manually by using the VAT Information Exchange System (VIES) website or by using a script to do it automatically by accessing the VIES web service via SOAP. The SOAP web service option is faster and less error prone so we came up with a simple script to check if a VAT identification number is valid. Unfortunately there is no RESTful API for the VIES service, so we have to install a library to generate the SOAP requests. Here's what you need to do in order to check VAT identification numbers:

The requirements:

• Python 2.5 or greater - most web servers have it installed by default
• the SUDS Python library

You can install the SUDS library using pip (a Python package manager). Just run the following command in your command line:

pip install suds

Once you have SUDS installed create a new Python file with the following code:

from suds.client import Client
from urllib import getproxies

VIES_URL = "http://ec.europa.eu/taxation_customs/vies/checkVatService.wsdl"
client = Client(VIES_URL, proxy=getproxies())
response = client.service.checkVat(countryCode='RO', vatNumber='28653549')
print response

The above code will check the VIES database for a company with the RO28653549 identification number which by chance happens to be our VAT number. You will have to replace the countryCode and vatNumber parameter values with your own values in order to validate other VAT identification numbers.

To make the script more useful you can create a function to check the formatting of the identification number based on the country code. Here are the formats for each individual country to help you get started:

The VAT Information Exchange System website has more information on how the data is gathered, and what to do in case the your VAT identification number is invalid.