(1) Whether a person is entitled to a writing-down allowance or a balancing allowance, or liable to a balancing charge, for a chargeable period is determined separately for each pool of qualifying expenditure and depends on—

(a) the available qualifying expenditure in that pool for that period (“AQE”), and

(b) the total of any disposal receipts to be brought into account in that pool for that period (“TDR”).

(2) If AQE exceeds TDR, the person is entitled to a writing-down allowance or a balancing allowance for the period.

(3) If TDR exceeds AQE, the person is liable to a balancing charge for the period.

(4) The entitlement under subsection (2) is to a writing-down allowance except for the final chargeable period when it is to a balancing allowance.

(5) The final chargeable period is given by section 65.

(6) Subsection (2) is subject to [section 104F (special rate cars: discontinued activity continued by relevant company) and]¹ section 110(1) (overseas leasing: allowances prohibited in certain cases).