How do you validate a VAT number?

To validate a VAT number, you can use the European Commission's VIES (VAT Information Exchange System) tool, which checks the validity of VAT numbers issued by EU member states. Enter the VAT number and the corresponding country code to verify its authenticity and status. Additionally, ensure that the format of the VAT number adheres to the specific country's rules, as each country has its own structure. For non-EU countries, consult the relevant tax authority or use dedicated validation services.