Most of us get our tax back automatically thanks to the new system where IRD calculates the tax you have paid versus the tax you should have paid.  This system came in in 2019, however, if you had tax owed to you prior to that it may still be sitting there waiting for you. Normally when you are on wages, you are taxed at the correct rate of tax and so there should be no need to "catch up" at the end of the financial year. Provided all is as it should be, you remained in the same employment, your family circumstances didn't change and you are not in a business of your own.  These, and so many other things can have an effect on whether the calculation is correct or not. For example, if you were in a high paying job, say $150,000 gross then the tax would be deducted (incl ACC) at $42,414.  However if you were only in that role for 6 months and earned $75,000 the tax that would be deducted is $16,713(including ACC), but you would have paid half of the amount due for th...