Computation of insurance business profits: actuarial surplus and statutory account profits determine taxable income with prescribed adjustments. Life insurance profits are computed separately by taking the annual average of the actuarial valuation surplus for the last inter valuation period, excluding earlier-period surpluses/deficits, and including any expenditure not admissible under general business deduction rules; for inter valuation periods exceeding twelve months, tax-crediting follows the annual average of tax deducted at source. Other insurance profits equal profit before tax as per statutory accounts with add backs for non deductible expenditures, adjustments for investment realisation gains/losses and provisions, and a deductible reserve for unexpired risks.