The Treasury may by order substitute a different percentage for the percentage that is at any time specified in section 356C(2) (calculation of allowance as a percentage of capital expenditure).

The Treasury may by order amend the number that is at any time specified in section 356CA(1) or (2) (cap on production, or estimated production, at a site for the purposes of onshore allowance).

An order under subsection (1) or (2) may include transitional provision.