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rubygems Specs

Validates european vat numbers. Standalone or as a ActiveModel validator.

A note on Brexit

Valvat supports validating VAT-IDs from the UK by syntax, checksum and using the HMRC API (for backwards compatibility only with the :uk option set to true). Validation against the VIES web service stopped working early 2021.

Northern Ireland received its own VAT number prefix - XI which is supported by VIES web service so any XI-prefixed VAT numbers should be validated as any EU VAT number.


  • Simple syntax verification
  • Lookup via the VIES web service
  • (Optional) lookup via the HMRC web service (for UK VAT numbers)
  • ActiveModel/Rails integration
  • Works standalone without ActiveModel
  • Minimal runtime dependencies
  • I18n locales for language specific error messages in English, German, French, Spanish, Italian, Portuguese, Polish, Swedish, Dutch, Danish, Czech, Slovakian, Hungarian, Bulgarian, Romanian, Latvian, Catalan, Norwegian, and Finnish.
  • Experimental checksum verification

valvat is tested and works with ruby MRI 2.6/2.7/3.0/3.1/3.2, jruby and ActiveModel 5/6/7. If you need support for ruby down to 1.9.3 and ActiveModel 3 and 4 use v1.0.1.


Add it to your Gemfile:

gem 'valvat'

And run:

$ bundle

Or install it yourself as:

$ gem install valvat

Validate the syntax of a VAT number

To verify the syntax of a vat number:"DE345789003").valid?
# => true or false

It is also possible to bypass initializing a Valvat instance and check the syntax of a vat number string directly with:

# => true or false

Validate against the VIES / HMRC web service

To check if the given vat number exists via the VIES or HMRC web service:"DE345789003").exists?
# => true or false or nil

Or to lookup a vat number string directly:

# => true or false or nil

To keep backwards compatibility lookups of UK VAT numbers against the HMRC API are only performed with the option :uk set to true.

Valvat::Lookup.validate("GB553557881", uk: true)
# => true or false or nil

Without this option the lookup of UK VAT number always returns false.

IMPORTANT Keep in mind that the web service might be offline at some time for all or some member states. If this happens exists? or Valvat::Lookup.validate will return nil. See Handling of maintenance errors for further details.

Details & request identifier

If you need all details and not only if the VAT is valid, pass {detail: true} as second parameter to the lookup call."IE6388047V").exists?(detail: true)
=> {
  :country_code=> "IE", :vat_number => "6388047V", :valid => true,
  :request_date =>, :name=> "GOOGLE IRELAND LIMITED",
} or false or nil

According to EU law, or at least as Austria sees it, it's mandatory to verify the VAT number of every new customer, but also to check the VAT number periodicaly. To prove that you have checked the VAT number, the web service can return a request_identifier.

To receive a request_identifier you need to pass your own VAT number in the options hash. In this example, Google (VAT IE6388047V) is checking the validity of eBays VAT number (LU21416127)"LU21416127").exists?(requester: "IE6388047V")
=> {
  :country_code=>"LU", :vat_number => "21416127", :valid => true,
  :request_date =>, :name=>"EBAY EUROPE S.A R.L.",
  :address => "22, BOULEVARD ROYAL\nL-2449  LUXEMBOURG",
  :company_type => nil, :request_identifier => "some_uniq_string"
} or false or nil

If the given requester is invalid, a Valvat::InvalidRequester error is thrown.

When requesting a request_identifier for a GB VAT number, the requester must be your own GB number; a EU VAT number won't work.

Note that when validating UK VAT numbers using the HMRC service, the detail output is modified to match the one from VIES more closely with slight differences remaining:

  1. The request_date will actually be a (more precise) Time instead of a Date
  2. The address string will join lines using \n instead of , so it's more acurate and can be displayed nicely.

Handling of maintenance errors

From time to time the VIES web service for one or all member states is down for maintenance. To handle this kind of temporary errors, Valvat::Lookup#validate returns nil by default to indicate that there is no way at the moment to say if the given VAT is valid or not. You should revalidate the VAT later. If you prefer an error, use the raise_error option:"IE6388047V").exists?(raise_error: true)

This raises Valvat::ServiceUnavailable or Valvat::MemberStateUnavailable instead of returning nil.

Visit for more accurate information at what time the service for a specific member state will be down.

Handling of other errors

All other errors accuring while validating against the web service are raised and must be handled by you. These include:

  • Valvat::InvalidRequester
  • Valvat::BlockedError
  • Valvat::RateLimitError
  • Valvat::Timeout
  • all IO errors

If you want to suppress all known error cases. Pass in the raise_error option set to false:"IE6388047V").exists?(raise_error: false)

This will return nil instead of raising a known error.

Set options for the Net::HTTP client

Use the :http key to set options for the http client. These options are directly passed to Net::HTTP.start.

For example to set timeouts:"IE6388047V").exists?(http: { open_timeout: 10, read_timeout: 10 })

Skip local validation before lookup

To prevent unnecessary requests, valvat performs a local syntax check before making the request to the web service. If you want to skip this step (for any reason), set the :skip_local_validation option to true.

Experimental checksum verification

valvat allows to check vat numbers from AT, BE, BG, DE, DK, ES, FR, FI, GR, IE, IT, LU, NL, PL, PT, SE and SI against a checksum calculation. All other member states will fall back to a basic syntax check:"DE345789003").valid_checksum?
# => true or false

These results are more valuable than a simple syntax check, but keep in mind: they can not replace a lookup via VIES or HMRC.

IMPORTANT This feature was tested against all vat numbers I could get my hand on, but it is still marked as experimental because these calculations are not documented and may return wrong results.

To bypass initializing a Valvat instance:

# => true or false

Usage with ActiveModel / Rails


When the valvat gem is required and ActiveModel is already loaded, everything will work fine out of the box. If your load order differs just add

require 'active_model/validations/valvat_validator'

after ActiveModel has been loaded.

Simple syntax validation

To validate the attribute vat_number add this to your model:

class MyModel < ActiveRecord::Base
  validates :vat_number, valvat: true

Additional lookup validation

To additionally perform an lookup via VIES:

validates :vat_number, valvat: { lookup: true }

To also perform an lookup via HMRC for UK VAT numbers:

validates :vat_number, valvat: { lookup: { uk: true } }

By default this will validate to true if the web service is down. To fail in this case simply add the :fail_if_down option:

validates :vat_number, valvat: { lookup: { fail_if_down: true } }

You can pass in any options accepted by Valvat::Lookup#validate:

validates :vat_number, valvat: { lookup: { raise_error: true, http: { read_timeout: 12 } } }

Additional (and experimental) checksum validation

To additionally perform a checksum validation:

validates :vat_number, valvat: { checksum: true }

Additional ISO country code validation

If you want the vat number’s (ISO) country to match another country attribute, use the match_country option:

validates :vat_number, valvat: { match_country: :country }

where it is supposed that your model has a method named country which returns the country ISO code you want to match.

Allow blank

By default blank vat numbers validate to false. To change this add the :allow_blank option:

validates :vat_number, valvat: { allow_blank: true }

Allow vat numbers outside of europe

To allow vat numbers from outside of europe, add something like this to your model (country_code should return a upcase ISO country code):

class MyModel < ActiveRecord::Base
  validates :vat_number, valvat: true, if: :eu?

  def eu?


To split a vat number into the country code and the remaining chars:

# => ["AT", "U345789003"]

# => ["AT", "U345789003"]

Both methods always return an array. If it can not detect the country or the given country is located outside of europe it returns [nil, nil]. Please note that this does not strictly return the ISO country code: for greek vat numbers this returns the ISO language code 'EL' instead of the ISO country code 'GR'.

To extract the ISO country code of a given vat number:"EL7345789003").iso_country_code
# => "GR"

To extract the vat country code (first two chars in every european vat number):"EL7345789003").vat_country_code
# => "EL"

To normalize a vat number:

# => "ATU345789003"

This basically just removes trailing spaces and ensures all chars are uppercase.

Usage with IPv6

There seems to be a problem when using the VIES service over IPv6. Sadly this is nothing this gem can address. For details and proposed solutions have a look at this question on StackOverflow. Thanks to George Palmer for bringing up this issue.


Contributions by


Copyright (c) 2011-2022 mite GmbH

Beyond that, the implementation is licensed under the MIT License.

Code was originally extracted from our time tracking webapp mite.