s 426 Pre-trading expenditure
A person’s entitlement to an allowance for a chargeable period is to a balancing allowance if— (a) the expenditure is qualifying expenditure under— (i) section 401(4) (pre-trading exploration expenditure where exploration etc. has ceased before first day of trading), or (ii) section 402 (pre-trading expenditure on plant or machinery), and (b) the first day of trading occurs in that chargeable period.