15(1)Any tax with which a person is chargeable and which is not paid by the time by which paragraph 11(1) above requires it to be paid shall carry interest from that time until payment.U.K.
(2)Sub-paragraph (1) above applies to any such tax as is there mentioned whether or not payment of it is postponed under section 55 of the Taxes Management Act 1970 as applied by paragraph 18 below.
(3)Any amount of tax which becomes repayable shall carry interest—
(a)in the case of tax in respect of which interest has been paid under sub-paragraph (1) above, from the time by which paragraph 11(1) above requires the tax to be paid until it is repaid;
(b)in any other case, from the time when paragraph 11(1) above requires the tax to be paid (or, if later, the time when it is paid) until it is repaid.
(4)The rate of interest under this paragraph for any period shall be that applying for that period for the purposes of sections 86 and 87 of the said Act of 1970.
(5)Interest payable under sub-paragraph (1) above shall be paid without any deduction of income tax and shall not be allowed as a deduction in computing income, profits or losses for any tax purposes; and interest paid under sub-paragraph (3) above shall be disregarded in computing income, profits of losses for any such purpose.