Hello HCYT, 

Welcome to the Community page, 

So there should be a code called No VAT that you can use. If that is not there to select then you may need a VAT code refresh done. So you would need to ring the support line on 0808 234 5337 and they will be able to raise it up and get it done for you the line is open mon to fri 8am to 7pm and is free from UK mob & landlines.