A valuation of the assets and liabilities of an occupational pension scheme conducted according to various actuarial assumptions, for example, relating to future investment performance, salary increases and mortality. The scheme actuary appointed in relation to the scheme under section 47 of the Pensions Act 1995 must conduct the valuation. Detailed professional guidance stipulates the methods the actuary must follow. The scheme trustees must commission formal valuations every three years, and obtain annual updating reports from the actuary in the interim.