Paragraph 13 InterestI1I2

If the whole or part of a penalty imposed under paragraph 3 or 6 is not paid by the day by which it is required to be paid, the unpaid balance carries interest at an annual percentage rate of 5% plus the Bank of England base rate.

But the IFR may, by notice to the person on whom the penalty is imposed, provide that this paragraph does not apply in relation to the penalty.