Question: how to work out how much vat you owe?
Answer: Take the gross amount of any sum (items you sell or buy) – that is, the total including any VAT – and divide it by 117.5, if the VAT rate is 17.5 per cent. (If the rate is different, add 100 to the VAT percentage rate and divide by that number.) Multiply the result from Step 1 by 100 to get the pre-VAT total.