(1) The Principal Act is amended -

(a) in section 520(1), in the definition of "relevant payment", by substituting the following for paragraph (ii):

"(ii) relevant payments as defined for the purpose of Chapter 2 of this Part,",

(b) in section 525(6) by substituting "that Chapter" for "section 531(1)",

(c) in section 530(1) by inserting the following after the definition of "certified subcontractor":

"'chargeable period' has the same meaning as in section 321(2);",

(d) in section 530(1) by inserting the following after the definition of "the contractor":

"'deducted tax' has the meaning given to it in section 530P;

'deduction authorisation' has the meaning given to it in section 530D;

'deduction summary', in relation to a return period, means a statement issued by the Revenue Commissioners to a registered principal setting out, in summary form, the details contained in deduction authorisations issued to that principal during that return period, adjusted, where adjustments are required, in accordance with regulations made under this Chapter, and includes a statement that no such deduction authorisations were issued, where that was the case;",