First you need to record all of your income you received during the year and record of all your tax deductible expenses. Source documentation that you should keep are income invoices as well as receipts/invoices for purchases made. You should organise your records into categories such as payments you’ve received; expenses related to payments you’ve paid, asset acquisition or disposal documents if you hold, buy and sell shares. We recommend following the ATO guidelines of holding your records for at least a minimum period of five years and preferably in a electronic format.