Box 1 - VAT due on sales and other outputs in the period. Box 2 - VAT due from you on acquisitions of goods from other EC Members Box 3 - the totals of boxes 1 + 2 Box 4 - the input tax you are entitled to claim for the period ie purchases / expenses (make sure you have receipts to back up what you are claiming). Box 5 - the difference between the figures from boxes 3 + 4. If in box 3 greater than box 4, this is what you must pay HMRC, if it is less HMRC pays you !