Finding the gross amount of any receipt of income which is actually paid net of income tax. This allows a taxpayer’s total gross income to be calculated; for example, if a UK taxpayer receives £78 net of tax and the tax rate is 22 per cent, their grossed up income is £100. Any allowances due are then subtracted to find taxable income, and tax payable. The total tax payable is compared with tax already deducted at source: if too little tax has been deducted the taxpayer then gets a demand for the remainder, and if too much tax has been deducted the taxpayer gets a refund.