The ATO has a clear message this year: slow down and get it right. Early lodgers are far more likely to make mistakes.

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The ATO automatically pre-fills information from your employer, banks, government agencies and health funds into your tax return to help you get it right the first time, but if you wait until late July to lodge, most pre-fill information about your wages, bank interest, government payments and private health insurance details will be pre-filled.
Also, things to check while you wait for pre-fill to be complete:
Once pre-filled data is available, you still should cross-check the figures against your own records, particularly for bank interest, dividends and government payments.
If something looks wrong, contact the provider so corrections can flow through to the ATO.
If you realise after lodgement that something’s missing or incorrect, you can fix it through the with an amended return.
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