At the end of each relevant accounting period of the company (starting with the first) the streamed opening negative amount in relation to a territory is to be reduced (or further reduced) by the amount of any relevant profits amount of the company for the territory for the accounting period (but not to below nil).

In any relevant accounting period of the company for which there is a reduction under subsection (1) in relation to a territory, section 18A(1) does not apply in relation to the relevant profits amount of the company for the territory for the accounting period.

But in the case of the last relevant accounting period of the company for which there is a reduction under subsection (1) in relation to a territory, section 18A(1) is disapplied by subsection (2) only in relation to so much of the relevant profits amount of the company for the territory for the accounting period as is equal to the streamed opening negative amount in relation to the territory at the beginning of the accounting period.

The company may, in its company tax return for that relevant accounting period, specify to which part of the relevant profits amount of the company for the territory for the accounting period section 18A(1) is to apply by virtue of subsection (3).