We use the VIES system to validate VAT's. You'll notice on the page that as of 01/01/2021, the VoW service to validate UK (GB) VAT numbers ceased to exist. If you're using a UK VAT, we will not be able to validate it and you will be charged tax.
Our company is registered for VAT in the UK and has a UK company address. Our UK VAT is listed below as well as on your purchasing invoice.
UK VAT: 369 1389 57