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How is interest calculated?

Guide to how interest is calculated.

Last updated 26 June 2007

Interest is generally calculated as follows:

(Number of days ÷ 365 [see Note]) × amount of payment × (interest rate for period ÷ 100)

Note: 366 for a leap year

Is interest assessable income?

Yes, interest is assessable income. Include any interest on your tax return in the year it is paid to you or in the year it is set off or applied against another tax debt you had with us.