http://www.legislation.gov.uk/id/asp/2014/16

PART 10Enforcement of payment of tax

CHAPTER 1Enforcement: general

Recovery of penalties and interest

226Recovery of penalties and interest

The provisions of this Chapter have effect in relation to the recovery of any unpaid amount by way of—

(a)

penalty, or

(b)

interest (whether on unpaid tax or penalty),

as though that amount were an amount of unpaid tax.