(1) Section 126AA of the Principal Act is amended -

(a) by substituting the following for subsection (1):

"(1) In this section -

'Act of 1997' means the Taxes Consolidation Act 1997 (No. 39 of 1997);

'appropriate tax' has the meaning given to it by section 256 of the Act of 1997;

'assessable amount', in relation to a relevant person, means the relevant retention tax in relation to the person;

'base year' means the year -

(a) 2011, in respect of the years 2014, 2015 and 2016,

(b) 2015, in respect of the years 2017 and 2018,

(c) 2017, in respect of the years 2019 and 2020, and

(d) 2019, in respect of the year 2021;

'due date' means, in relation to a year, 20 October in the year concerned;

'relevant business' means the business of a relevant person of taking and holding relevant deposits (within the meaning of section 256 of the Act of 1997) in respect of which the person was obliged to pay any amount under section 258 or 259 of that Act;

'relevant person' means a person who, in a base year, comes within the meaning of paragraph (a) or (b) of the definition of 'relevant deposit taker' in section 256(1) of the Act of 1997 and who -

(a) is obliged in the base year to pay -