(1)This section applies if—
(a)a penalty period has begun under section 170 because P has failed to make a payment (“payment A”), and
(b)before the end of the period, P fails to make another payment (“payment B”) falling within the same item in the table in section 168 as payment A.
(2)In such a case—
(a)section 170(2) and (3) do not apply to the failure to make payment B,
(b)P is liable to a penalty under this section for that failure, and
(c)the penalty period that has begun is extended so that it ends with the day 12 months after the date specified in or for the purposes of column 4 for payment B.
(3)The amount of the penalty under this section is determined by reference to the number of defaults that P has made during the penalty period.
(4)If the default is P’s first default during the penalty period, P is liable, at the time of the default, to a penalty of 2% of the amount of the default.
(5)If the default is P’s second default during the penalty period, P is liable, at the time of the default, to a penalty of 3% of the amount of the default.
(6)If the default is P’s third or subsequent default during the penalty period, P is liable, at the time of the default, to a penalty of 4% of the amount of the default.
(7)For the purposes of this section—
(a)P makes a default when P fails to pay an amount of tax in full on or before the date on which it becomes due and payable,
(b)in accordance with subsection (1)(b), the references in subsections (3) to (6) to a default are references to a default in relation to the tax to which payments A and B relate,
(c)a default counts for the purposes of those subsections if (but only if) the period to which the payment relates is less than 6 months,
(d)the amount of a default is the amount which P fails to pay.
(8)A penalty period may be extended more than once under subsection (2)(c).