Section 185: Change from realisation basis to mark to market
700.This section is concerned with a change from the realisation basis to “mark to market” accounting. It is based on paragraph 8 of Schedule 22 to FA 2002. The corresponding rule for income tax is in section 236 of ITTOIA.
701.“Mark to market” is a basis of accounting used by traders in financial assets. Instead of carrying the assets in the books at cost, financial traders draw up accounts to show the assets at fair value at the accounting date. But for tax purposes the realisation basis may have been used.
702.In the first period in which mark to market is adopted for tax purposes, the opening stock may be valued at a higher (market) value than the closing stock of the previous period. Or a financial asset may have been carried in the accounts at cost but appear as a deduction in a later period at fair value. In either case, there is an adjustment within section 182.
703.As in section 184, the adjustment is postponed until the asset is realised.