Amendment of self-assessment during enquiry to prevent loss of taxU.K.
30(1)If after notice of enquiry has been given and [while the enquiry is in progress in relation to a matter] [an officer of Revenue and Customs] [forms] the opinion—U.K.
(a)that the amount stated in the company’s self-assessment as the amount of tax payable is insufficient, and
(b)that unless the assessment is immediately amended there is likely to be a loss of tax to the Crown,
[he] may by notice to the company amend its self-assessment to make good the deficiency [so far as it relates to the matter].
(2)In the case of an enquiry which under paragraph 25(2) is limited to matters arising from an amendment of the return, sub-paragraph (1) above only applies so far as the deficiency is attributable to the amendment.
(3)An appeal may be brought against an amendment of a company’s self-assessment by [an officer of Revenue and Customs] under this paragraph.
(4)Notice of appeal must be given—
(a)in writing,
(b)within 30 days after the amendment was notified to the company,
(c)to the officer of the Board by whom the notice of amendment was given.
[(5)None of the steps mentioned in section 49A(2)(a) to (c) of the Taxes Management Act 1970 may be taken in relation to the appeal before the completion of the enquiry.]
[(6)For the purposes of this paragraph, the period during which an enquiry is in progress in relation to any matter is the whole of the period—
(a)beginning with the day on which notice of enquiry is given, and
(b)ending with the day on which a partial closure notice is issued in relation to the matter or, if no such notice is issued, a final closure notice is issued.]