How do I know the VAT number on my suppliers invoice is genuine?

It’s a good idea to check any VAT number you have doubts about, as you can’t reclaim the VAT charged if the VAT registration is invalid. The quickest way to do this is to ring the VAT helpline on 0845 010 9000. The VAT officer will tell you if the VAT number and address details you read outmatch theirs. If they don’t match, they won’t tell you the details they have on file, but then you know you have a problem, so go back to your supplier.