(1) Subject to the provisions of this section, where a person gives notice of appeal under section 83 and, before the appeal is determined by a tribunal, [HMRC]¹ and the appellant come to an agreement (whether in writing or otherwise) under the terms of which the decision under appeal is to be treated—

(a) as upheld without variation, or

(b) as varied in a particular manner, or

(c) as discharged or cancelled,

the like consequences shall ensue for all purposes as would have ensued if, at the time when the agreement was come to, a tribunal had determined the appeal in accordance with the terms of the agreement ...².

(2) Subsection (1) above shall not apply where, within 30 days from the date when the agreement was come to, the appellant gives notice in writing to [HMRC]¹ that he desires to repudiate or resile for the agreement.

(3) Where an agreement is not in writing—

(a) the preceding provisions of this section shall not apply unless the fact that an agreement was come to, and the terms agreed, are confirmed by notice in writing given by [HMRC]¹ to the appellant or by the appellant to [HMRC]¹, and

(b) references in those provisions to the time when the agreement was come to shall be construed as references to the time of the giving of that notice of confirmation.

(4) Where—

(a) a person who has given a notice of appeal notifies [HMRC]¹, whether orally or in writing, that he desires not to proceed with the appeal; and

(b) 30 days have elapsed since the giving of the notification without [HMRC]¹ giving to the appellant notice in writing indicating that they are unwilling that the appeal should be treated as withdrawn,

the preceding provisions of this section shall have effect as if, at the date of the appellant’s notification, the appellant and [HMRC]¹ had come to an agreement, orally or in writing, as the case may be, that the decision under appeal should be upheld without variation.

(5) References in this section to an agreement being come to with an appellant and the giving of notice or notification to or by an appellant include references to an agreement being come to with, and the giving of notice or notification to or by, a person acting on behalf of the appellant in relation to the appeal.