(1) The amount of the tax credits and standard rate cut-off point appropriate to an employee for a year shall be determined by an inspector who for that purpose may have regard to any of the following matters, namely -

(a) the reliefs from income tax to which the employee is entitled for the year,

(i) so far as the employee's title to those reliefs has been established at the time of the determination, or

(ii) where a claim for those reliefs (including relief under section 469 of the Act) has been made, prior to the end of the year, through such electronic means as the Revenue Commissioners make available;

(b) the emoluments of the employee for the year;