The capital gains section in myTax asks about any CGT events during the year — selling shares, ETFs, crypto, or property — and calculates your net capital gain after applying any 50% discount and available losses. It's one of the more complex sections on the form, and getting the cost base or discount eligibility wrong is easy to do without realising it. This is one of the sections AusTax AI's agents spend the most time double-checking, because a single wrong date can flip whether the 50% discount applies.
What counts as a CGT event I need to report?
A CGT event happens whenever you dispose of an asset subject to capital gains tax — most commonly selling shares or ETF units, disposing of crypto (including trading one crypto for another, not just cashing out to AUD), or selling an investment property. Your main residence is normally exempt, but investment and second properties aren't. myTax separates "capital gains from a trust distribution" — usually pre-calculated on your managed fund's annual tax statement — from gains you calculate yourself on shares, crypto, or property you disposed of directly.
How does the 50% CGT discount work in the form?
If you're an Australian resident individual and held the asset for 12 months or more before disposing of it, you can generally discount your capital gain by 50% before it's added to your taxable income. myTax applies this once you confirm the holding period for each asset — get the dates wrong (for example, counting from a purchase confirmation date rather than the actual trade date) and you can either miss out on a discount you're entitled to or claim one you're not.
What about capital losses?
| Situation | How it's treated |
|---|---|
| Capital loss this year, capital gain this year | Loss offsets the gain before any discount is applied |
| Capital loss this year, no gain this year | Carried forward indefinitely to offset a future capital gain |
| Capital loss generally | Can only offset capital gains — never ordinary income like salary |
In short, a capital loss is only ever useful against a capital gain, in this year or a future one — it can't reduce tax on your wages.
Where does this get complicated fast?
Multiple parcels of the same share bought at different times and prices, corporate actions (buybacks, rights issues, demergers) that adjust your cost base, crypto-to-crypto trades that count as disposals even without cashing out, and inherited or gifted assets with their own cost-base rules are the situations that most often trip people up in this section. AusTax AI's document review flags multi-parcel share sales and crypto disposals for manual cost-base checking rather than trying to auto-calculate them silently. See our beginner's guide to capital gains tax on shares for how cost base and the discount work in more detail before you tackle the myTax form itself.
When is it worth getting help with this section?
If your CGT events are limited to a single parcel of shares sold in full, the form is usually straightforward to complete yourself. Once you're dealing with multiple parcels, crypto trading history, property, or trust distributions with foreign income components, the calculations get harder to get right without support — this is squarely the kind of return where a second set of eyes catches things the form itself won't flag for you.
Quick checklist
- Confirm exact acquisition and disposal dates for the 12-month discount test
- Separate trust/managed fund CGT amounts (from your annual tax statement) from gains you calculate yourself
- Check whether any prior-year capital losses are available to offset this year's gain
- Keep contract notes and cost-base records — the ATO (ATO guidelines) can ask for them well after lodgment
If you realise after lodging that you missed a CGT event, our guide on amending a tax return in myTax covers that process; for the rest of the form, see our step-by-step myTax guide.
a registered tax agent (see the directory) If your return also involves rental income or other investment complexity, the same tier applies once all the relevant details are in.
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*Disclaimer: This is general information only and does not constitute personal tax advice. Consult a registered tax agent for advice tailored to your specific situation. Always verify against the latest ATO guidelines at ato.gov.au.*