The relevant fees are specified in Rules AU-6.2.3 to AU-6.2.5 below: different fees are specified for Category 1, Category 2 and Category 3 investment firms. The fees due in April are those due for the same calendar year, but are normally calculated on the basis of the firm's financials for the previous calendar year: i.e. the fee payable in April 2007 (for example), is that due for the calendar year 2007, and is calculated using the audited financial statements for 2006. Where a licensee does not operate its accounts on a calendar-year basis, then the most recent audited financial statements available are used instead.