It is important to be aware of the difference between the terms 'income year' and 'tax assessment year'. Income year is the year in which an income or expense arises or the year in which you have taxable capital at the end of the year. Tax assessment year is the year after the income year and the year in which the tax return for the income year must be submitted and the tax for the income year calculated. This means that the tax return for the 2015 income year is submitted in 2016.
You should also note that there is a difference between independent tax assessment and separate tax assessment; see the explanation below.
You do not need to submit documentation with the tax return, but you must be able to present it upon request.