Why was customer's VAT number invalid?

For businesses located within EU, we are checking the VAT number with the VIES system (the Europe official system for validating VAT numbers). When the VAT is not being validated, that might happen for two reasons:

1. The VIES system is down. From time to time it might happen that the validation system from your country or entire system to have some problems. In such situations, we cannot process your payment before the European Commission gets the system back to working state. Most of the times, this is a temporary thing and the problem is solved within minutes. You can check the status of the VIES system at anytime, by visiting their Self Monitoring report.
2. Although if the customer has a valid VAT number in their country, it might not be registered inside the European Union. To find out if the number is valid, you can always check it on the VIES website. For more details about this problem it is always best to contact your local authorities and ask for more details.