Frequently Asked Questions (FAQ)

Euvat is taking over some Core Models and Controllers to change the Magento default way of calculating Taxes and handling Tax related customer data. Due to this, Euvat may get into conflict with other extensions which are set to take over (also called 'rewrite') a Core Model or Controller Euvat is requiring.

We have carefully designed Euvat to rewrite Models and Controllers at a minimum level, however some 3rd party extensions may not show the same quality of design. This is how you may resolve such extension conflicts:

  1. See the FAQ entry below to find the extension causing the conflict
  2. Contact our Support Team with a detailed description of your issue. You may want to prepare a backup of your Magento Site and Magento Database to provide to our Support Team if asked to do so.



As to our current knowledge, such conflicts are resolveable. Please understand that any associated modifications required are being documented here for your own implementation.

Disable all 3rd-party Extensions installed in your Magento Site in a step-by-step order. For each disabled extension, try your site again. If the conflict disappears, the last extension disabled is in conflict with Euvat:

System » Configuration » Advanced


Disable the extensions, except the one starting with 'Mage_' which usually are Magento Core Extensions. In some cases 3rd Party Developers use the 'Mage_' Prefix for their extensions too - which is discouraged to do - so look also for names you recognize as one installed non-core extension.

Alternatively to disable a Extension completely, you may want to temporarily remove its related .xml configuration file located in
app/etc/modules.

Always temporarily disable the Cache when performing these actions under System » Cache Management » All Cache » Disable

You may also use this extension to find which Extensions are rewriting models required to be handled by EuVAT: Developer Helper.
The models required to be handled by EuVAT are documented here, if a extension is also rewriting these models then contact us.



When having found the extension, which creates the conflict with Euvat, contact our Support Team which may give you directions on how to resolve this to get the full functionality of Euvat.

If in your shop the shopping cart is showing a Zero VAT, or a incorrect VAT, for a Guest User (a user currently not logged-in), then this may be caused by Tax Rules currently defined in your Shop that create this behaviour.

To identify the cause of this Tax Calculation behaviour proceed as described here:

  1. Remove any Tax Rules, other than the one as specified to EuVat in the documentation for the Setup with Customer Groups or the Setup with Customer Tax Classes.
  2. Set the Default Tax Destination Calculation to the Country of Origin your Shop is in.
  3. Set the EuVat configuration option Allow Country Tax Rules to No, to lock the Tax Calculation to the Tax Region set in the Default Tax Destination Calculation.



In case these actions still render a Zero VAT for Guest Visitors in their Shopping Cart, contact our Support Team with the following details:

  • A screenshot of your Tax Zones & Rates (Sales » Tax » Manage Tax Zones & Rates)
  • A Screenshot of your Tax Rules (Sales » Tax » Manage Tax Rules)
  • A Screenshot of the Details of each Tax Rule



If at registration of a new Customer Account, and there is a incorrect or invalid EU VAT ID Number entered, the registration will still take place. However that particular customer account will not get assigned as EU Business with valid VAT. If the address is within the EU such account is being assigned as EU Consumer, for addresses outside the EU such account is being assigned as Non-EU Customers.

To change this behaviour, and block registration of new customers with a EU VAT Number that did verify incorrect, you need to perform the changes described in Limit creation of new customer accounts to valid EU Businesses. You may leave the related configuration option at No to allow registration of Non-EU Business customers.

When performing these changes, a related message will be shown to customers trying to register when the entered EU VAT Number has failed validation:



In case you receive such a error message in your store:


This indicates that there is a service interruption or defect on the EU VIES Service. That message has nothing to do with the EuVAT Extension, it shows that the VAT Check with the EU VIES Service is currently disrupted.

See also this related message, generated by EuVAT, when experiencing such disruptions...

This is a known issue currently, as the access to the EU VIES service through IPv4 is different from IPv6. Our extension is not able to influence which IP-Stack will get used by your server when making the outgoing connection to the EU VIES service for validation of a VAT number.

With release 0.3.48 we have added provisions suggest by the EU VIES Team, however this may not help in your case. In addition you may ask your Hosting Provider to add the following to your servers IP configuration:

Create Preference on IPv4 connections

This is the preferred approach, if this is not possible or does not solve it refer to adding the EU VIES IP4-Addresses to the servers hosts file as shown below of this:

/etc/gai.conf (Linux Servers only)

precedence ::ffff:0:0/96 100



Tell IP to use IPv4 for the hosts of EU VIES

Be clear that in case the IP-Addresses of the EU VIES hosts change you may need to change these entries also, otherwise the outgoing validation will stop working:

/etc/hosts (Linux Servers) %SystemRoot%\system32\drivers\etc\hosts (Windows Servers)

147.67.119.3   ec.europa.eu
147.67.119.103 ec.europa.eu
147.67.136.3   ec.europa.eu
147.67.136.103 ec.europa.eu