The VIES validation service is a government maintained system that we rely on for validating the VAT numbers put into our system. As with any web service, they can have maintenance times or upgrades that cause a period of downtime, or they can be susceptible to unscheduled outages at times as well.
VAT number VIES VAT number validation service unavailable, please try again. later.
This error message indicates that some downtime of that nature happened, such that we received no response from their service when trying to validate the VAT number at signup or during a billing information update. Due to the requirement to validate VAT numbers that are used, there is not a way around the validation system at signup.
If you are trying to update existing billing information and receive this error, we recommend trying again after 24 hours. If the issue persists, Contact Support for further troubleshooting help.