The basic accounting for share-based payments for remuneration is quite simple – expense an amount over a vesting period. The main difficulties are associated with (a) determining a reliable fair value for the instrument, and (b) determining a reasonable estimate of the number of instruments that will not lapse during the vesting period. The former, fair value, is bound up in some reasonably sophisticated valuation procedures. The latter is a management-derived estimate that will depend upon internal judgments on a year-by-year basis, although by the end of the vesting period one will know how many options will vest. The determination of the fair value will be the more difficult aspect.