How to lodge your Australian tax return

You must lodge if you had tax withheld from any payment during the year, if your taxable income exceeded the tax-free threshold of $18,200, if you were a foreign resident with Australian income above a very low threshold, or if you are leaving Australia permanently.

You should lodge even if you are not required to, in one very common case: if tax was withheld and your income was below the threshold, the return is how you get it back. Students and part-time workers routinely leave hundreds of dollars with the ATO by not lodging.

If you genuinely do not need to lodge, submit a non-lodgement advice through ATO online services rather than doing nothing. It closes the year off and stops the ATO chasing you.

This is the single most useful piece of timing advice. Employers must finalise their Single Touch Payroll data — usually by 14 July. Banks, health funds, share registries and government agencies report through July. Most prefill data is complete by the end of July.

Lodging on 1 July against incomplete data is the most common self-inflicted problem. If you lodge and the ATO later receives data that changes your position, you have to amend, and if the amendment increases your tax you may owe interest.

Check your income statement is marked 'Tax ready' in ATO online services before you start. If an employer has not finalised, contact them — you cannot fix it from your end.

Sign in to myGov, go to ATO online services, and select Lodge under Tax. myTax walks through income, deductions, offsets and Medicare in order, showing an estimated refund or bill that updates as you go.

Check every prefilled figure against your own records rather than accepting it. Prefill is usually right but it is not guaranteed, and you remain responsible for the accuracy of your return.

Add anything the ATO does not know about: cash income, foreign income if you are a resident for tax purposes, capital gains from selling shares or property, rental income, and income from platforms like Airbnb or rideshare. Sharing-economy platforms now report to the ATO directly, so undeclared platform income is likely to be detected.

Nominate a bank account for the refund. Refunds are only paid electronically.

The general rule is three-part: the expense must directly relate to earning your income, you must have spent the money and not been reimbursed, and you must have a record. If any of the three fails, the deduction fails.

Common legitimate claims include work-related travel between workplaces (not home to work), tools and equipment, protective clothing and compulsory uniforms, self-education directly related to your current job, union fees and professional subscriptions, income protection insurance premiums, and the cost of managing your tax affairs.

Working from home has two methods. The fixed-rate method claims a set number of cents per hour worked from home, covering energy, internet, phone and stationery, and requires a record of hours actually worked. The actual-cost method claims the real work-related portion of each expense and requires far more documentation. The fixed rate changes periodically — check the current rate on the ATO site.

Motor vehicle claims use either the cents-per-kilometre method, capped at a set number of business kilometres per car per year, or the logbook method requiring a twelve-week logbook that stays valid for five years.

What cannot be claimed: ordinary commuting, plain clothes worn to work, childcare, most grooming, fines, and anything your employer reimbursed.

A registered tax agent can lodge on your behalf on a later timetable — typically up to 15 May of the following year — but only if you are on their client list by 31 October. This is the most valuable and least known feature of the agent system: registering with an agent before 31 October buys you months.

Check registration on the Tax Practitioners Board register before engaging anyone. It is an offence to charge for tax agent services without registration, and unregistered preparers leave you carrying the liability for their errors.

The fee is deductible in the following year's return. For a straightforward salaried return, myTax is usually adequate; for rental properties, capital gains, business income, foreign income or anything with a genuine judgement call, an agent generally pays for itself.

If you cannot pay a tax bill, contact the ATO before the due date. Payment plans are routinely available, and general interest charges accrue on unpaid amounts. The ATO is markedly more accommodating to people who call before the deadline than to those who go quiet.