39(1)If the appellant notifies HMRC that it requires them to review the matter in question, HMRC must—U.K.
(a)notify the appellant of HMRC's view of the matter in question within the relevant period, and
(b)review the matter in question in accordance with paragraph 41.
(2)Sub-paragraph (1) does not apply if—
(a)the appellant has already given a notification under this paragraph in relation to the matter in question,
(b)HMRC have given a notification under paragraph 40 in relation to the matter in question, or
(c)the appellant has notified the appeal to the tribunal.
(3)In this paragraph “the relevant period” means—
(a)the period of 30 days beginning with the day on which HMRC receive the notification from the appellant, or
(b)such longer period as is reasonable.