The “Requester VAT Number” field is optional. As indicated in the settings page:
If you enter a valid EU VAT number, it will be passed to the EU VIES service with each EU VAT number validation request. With this information, the VIES service will return a a “consultation number”, which can be used as proof of the validity of VAT numbers entered by your customers, should your revenue office ask for such evidence.
Important
– Please make sure that you enter you VAT number without the country code prefix. The country code will be added automatically, by the EU VAT Assistant, using the country you selected above.
– From the 1st of January 2021, you can no longer enter a UK VAT number in this field. If you have a UK VAT number, please leave this field empty.
If you leave the “Requester VAT Number” field empty, then the VIES service won’t return a consultation number.
