This project is really old and unmaintained. It's kept here for legacy reasons.

We advice you to use this one instead : https://github.com/yolk/valvat

Use this plugin to validate VAT numbers for european countries.

This plugin is Rails 2.x-only, if you want the same functionnality for Rails 3, use my : vat_validator available at http://github.com/aurels/vat_validator

To validate a model field as a valid intracom VAT number :

validates_vat_number :vat_number

It may be optional like this :

validates_vat_number :vat_number, :allow_blank => true

If you want the VAT number's country to match another kind of country field, use the option :

validates_vat_number :vat_number, :country_method => :my_method

where it is supposed that your model has a method named 'my_method' which returns the country code you want to match. The available country codes available for Europa are: DE, AT, BE, BG, CY, DK, ES, EE, FI, FR, EL, HU, IE, IT, LV, LT, LU, MT, NL, PL, PT, GB, RO, SK, SI, SE and CZ.

Example :

class Invoice < ActiveRecord::Base validates_vat_number :vat_number, :country_method => :country_code

# Logic to return the country code
def country_code
  case country.downcase
    when 'belgium' then 'BE'
    when 'france'  then 'FR'
    when 'sweden'  then 'SE'
    # ...
    else nil
  end
end

end

As a gem in your environment.rb :

config.gem 'validates_vat_number'

As an old-school Rails plugin :

script/plugin install git://github.com/aurels/validates_vat_number.git

If you want to run the specs :

rake spec

This plugin in released under MIT license by Aurélien Malisart (see LICENSE file).

(c) http://aurelien.malisart.be