(1) The Treasury may by order provide that, in such cases as may be specified in the order, no section 45H allowance may be made unless a relevant certificate of environmental benefit is in force.

A “section 45H allowance” means a first-year allowance in respect of expenditure that is first-year qualifying expenditure under section 45H.

(2) A certificate of environmental benefit is one certifying that—

(a) particular plant or machinery, or

(b) plant or machinery constructed to a particular design,

meets the environmental criteria specified in relation to that description of plant or machinery by order under section 45H.

(3) A relevant certification of environmental benefit means one issued—

(a) by the Secretary of State or a person authorised by the Secretary of State;

(b) in the case of plant or machinery used or for use in Scotland, by the Scottish Ministers or a person authorised by them;

(c) in the case of plant or machinery used or for use in Wales, by the National Assembly for Wales or a person authorised by it;

(d) in the case of plant or machinery used or for use in Northern Ireland, by the Department of Enterprise, Trade and Investment in Northern Ireland or a person authorised by it.

(4) If a certification of environmental benefit is revoked—

(a) the certificate is treated for the purposes of this section as if it had never been issued, and

(b) all such assessments and adjustments shall be made as are necessary as a result of the revocation.

(5) If a person who has made a tax return becomes aware that, as a result of the revocation of a certificate of environmental benefit after the return was made, the return has become incorrect, he must give notice to [an officer of Revenue and Customs]¹ specifying how the return needs to be amended.

(6) The notice must be given within three months beginning with the day on which the person first became aware that anything in the tax return had become incorrect because of the revocation of the certificate.