66(1)HMRC and the appellant may agree that payment of an amount of tax should be postponed pending the determination of the appeal.
(2)The agreement may modify a determination by HMRC under paragraph 64.
(3)Where the agreement does so, it is to be treated in the same way as a settlement agreement under paragraph 61.
(4)The consequences of an agreement are to be the same as if the tribunal had, at the time when the agreement was entered into, made a direction to the same effect as the agreement.
(5)The existence of an agreement does not preclude a further determination by HMRC or direction by the tribunal modifying the agreement.
(6)An agreement—
(a)must be made in writing;
(b)may be made with a person acting on behalf of the appellant in relation to the appeal.