As a UK-based company, we are required by law to charge VAT if a valid VAT number is not provided for any company based in the EU.
Companies based in the UK are required to pay VAT regardless of a VAT number being provided or not.
If you do not have a VAT number please check the "I do not have a valid VAT number" checkbox.
If you are having issues applying your VAT number during purchase, please get in touch with us and we will be happy to assist.