Rule 148 of the Principal Rules is amended as follows:(a) by omitting from subrule (1) " rule 148 ," and substituting " rule 147 ," ;(b) by inserting in subrule (2)(b) ", including an allowance for the impact of the GST, within the meaning of the A New Tax System (Goods and Services Tax) Act 1999 of the Commonwealth" after "assessment" .