Most investors buy the same share more than once, at different prices and on different dates. Each purchase is a separate parcel. When you sell only some of your holding, you need to know which parcel you sold, because it changes both your cost base and whether the 50% discount applies (ATO: How to calculate your CGT).
You choose which parcel you sold
The ATO lets you identify which shares you disposed of. Many people use first in, first out(FIFO), selling the earliest parcel first, but you can choose the parcels that give the best result. The parcel you match sets the cost base, and its purchase date decides whether you held for more than 12 months.
A worked example
Say you bought CBA twice, then sold part of your holding:
- Parcel A: 100 shares on 1 March 2023, $90.00 each plus $10 brokerage. Cost base $9,010.
- Parcel B: 100 shares on 1 June 2024, $100.00 each plus $10 brokerage. Cost base $10,010.
- Sale: 150 shares on 1 May 2025 for $110.00 each ($16,500), less $15 brokerage, so $16,485 proceeds, or $109.90 per share.
Using FIFO, the 150 sold come from all of Parcel A and half of Parcel B:
- From Parcel A (100 shares): proceeds $10,990, cost base $9,010, gain $1,980. Held over two years, so it qualifies for the 50% discount.
- From Parcel B (50 shares): proceeds $5,495, cost base $5,005, gain $490. Held under 12 months, so no discount.
The two gains are treated differently. The $490 is taxed in full; the $1,980 is halved to $990 by the discount. With no losses to offset, the net capital gain added to your income is $1,480. Same shares, same sale, but the parcel split is what decides how much is discounted.
How CGT Mate handles it
CGT Mate matches your parcels first in, first out, works out each one separately, applies the discount only to the parcels that qualify, and gives you a parcel-by-parcel schedule and a CSV. Choosing specific parcels to minimise tax is something you or your accountant can do by hand; the tool shows the FIFO working as your starting point. See also our guide to CGT on shares and the 50% discount.