(1)This section applies if—
(a)a sum is payable to or by the Commissioners under a decree or extract issued in any court proceedings relating to a taxation matter (a “tax-related judgment debt”), and
(b)interest in relation to the tax-related judgment debt is included in or payable under the decree or extract.
(2)In a case where the rate of interest in relation to the tax-related judgment debt is stated in the decree or extract, the rate stated in relation to that debt may not exceed (and may not be capable of exceeding)—
(a)in the case of a sum payable to the Commissioners, the late payment interest rate, and
(b)in the case of a sum payable by the Commissioners, the special repayment rate.
(3)In a case where the rate of interest in relation to the tax-related judgment debt is not stated in the decree or extract but provided for by an enactment or rule of court (whenever passed or made), that enactment or rule is to have effect in relation to the debt as if for the rate for which it provides there were substituted—
(a)in the case of a sum payable to the Commissioners, the late payment interest rate, and
(b)in the case of a sum payable by the Commissioners, the special repayment rate.
(4)This section has effect in relation to interest for periods beginning on or after the day on which this Act is passed, regardless of—
(a)the date of the decree or extract in question, and
(b)whether interest begins to run on or after the day on which this Act is passed, or began to run before that date.
(5)In this section—
“the Commissioners” means the Commissioners for Her Majesty's Revenue and Customs;
“enactment” includes an Act of the Scottish Parliament or an instrument made under such an Act;
“late payment interest rate” means the rate provided for in regulations made by the Treasury under section 103(1) of FA 2009;
“special repayment rate” has the same meaning as in section 52 of F(No.2)A 2015 (and subsections (7) to (10) of that section apply for the purposes of this section as they apply for the purposes of that section);
“taxation matter” means anything the collection and management of which is the responsibility of the Commissioners (or was the responsibility of the Commissioners of Inland Revenue or Commissioners of Customs and Excise);
“working day” means any day other than a non-business day as defined in section 92 of the Bills of Exchange Act 1882.
(6)This section extends to Scotland only.