Crypto Cost Basis Methods in Australia: FIFO, LIFO, and Specific Identification

What a Cost Basis Method Is

When you sell or dispose of cryptocurrency, you need to calculate the capital gain or loss. The capital gain is the sale price minus the cost base: what you paid to acquire the coins, including trading fees and other acquisition costs. If you have made multiple purchases of the same asset at different prices over time (as is common with dollar-cost averaging), you have multiple “parcels” of the same asset, each with a different cost base.

As of 1 July 2027, CGT rules in Australia are set to change. Please visit this page for the revised tax rules.

A cost basis method is the rule that determines which parcel of a cryptocurrency you are deemed to have sold when you make a disposal. Different methods produce different cost bases for the same disposal, leading to different capital gains calculations, different capital gains tax outcomes, and potentially very different tax bills. Choosing and consistently applying the right method is one of the most impactful tax planning decisions available to crypto investors.

The Australian crypto tax overview establishes the general framework: each disposal is a CGT event, gains are assessable income, and the 50% CGT discount applies for assets held longer than 12 months. The cost basis method determines the specific cost base used for each disposal within that framework. The ATO crypto rules provide guidance on which methods are accepted.

 

What Actually Goes Into the Cost Base

The cost base is not only what you paid for the asset. Getting this wrong inflates the capital gain and overstates the tax owed, which is a costly error in the taxpayer’s own disfavour.

Broadly, the cost base of a crypto parcel can include:

• The AUD value of what you paid to acquire it, at the time you acquired it
• Brokerage and exchange trading fees on the acquisition
• Transaction costs incurred in acquiring or disposing of the asset, which for on-chain activity can include network gas fees
• Certain incidental costs of ownership and disposal

Two points where people commonly go wrong. First, the AUD value must be recorded at the time of the transaction, not converted later at some average rate. This matters most on crypto-to-crypto swaps, where no Australian dollars change hands but an AUD value still has to be established for both sides.

Second, fees are easy to lose. Exchange fees are often deducted from the asset received rather than charged separately, so they never appear as a line item and quietly go unrecorded. End of financial year statements from your exchange are the practical way to reconcile this.

FIFO: First In First Out

FIFO (First In First Out) is the ATO default method for crypto cost basis calculation. Under FIFO, when you sell some of a cryptocurrency, the parcels you acquired first are treated as sold first. If you bought 0.5 BTC in January, 0.5 BTC in June, and 0.5 BTC in December, and you sell 0.5 BTC in the following year, FIFO treats the January parcel as sold.

The practical implication of FIFO is that it tends to match disposals against older (and often lower-priced) acquisition parcels during bull markets. This can result in larger capital gains if the January purchase price was much lower than the December purchase price. However, FIFO also tends to maximise the number of parcels that qualify for the 12-month CGT discount, since older parcels are more likely to have been held for over 12 months.

FIFO is the default primarily because it is straightforward to apply and audit. The ATO reporting requirements expect consistent method application across the financial year. Most crypto tax calculators use FIFO as the default setting because it aligns with ATO expectations and is the least likely to be challenged in an audit.

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LIFO: Last In First Out

LIFO (Last In First Out) treats the most recently acquired parcel as the first sold. Using the same example, selling 0.5 BTC under LIFO would match against the December parcel (the most recent purchase) rather than the January parcel.

LIFO can be advantageous in a bull market if the most recently acquired parcel has a higher cost base (reducing the capital gain) or if matching against a recent parcel avoids a larger gain on a much older, much cheaper parcel. However, LIFO also tends to match disposals against parcels that do not yet qualify for the 12-month CGT discount if the recent purchases are less than 12 months old.

The ATO does not explicitly endorse LIFO, but it also does not explicitly prohibit it. The requirement is consistency: you must apply the same method throughout the financial year and from year to year unless there is a valid reason to change. Switching methods opportunistically to minimise tax in a specific year is not permitted and would constitute aggressive tax avoidance. Confirming the acceptability of LIFO with a registered tax agent before applying it is advisable.

 

Specific Identification

Specific identification allows you to nominate the exact parcel you are selling at the time of each disposal. If you have parcels from January, June, and December, you can choose to sell the June parcel specifically, using its exact cost base. This is the most flexible method and can be used to optimise each disposal individually: choosing parcels that minimise gains, maximise losses (for tax loss harvesting), or match parcels held over 12 months to qualify for the CGT discount.

Specific identification requires meticulous record-keeping. The ATO requires that the identification be made at the time of disposal (or shortly after), not retroactively at tax time. This means your crypto tax records must document which specific parcel was sold in each transaction. Most professional crypto tax calculators support specific identification, but it requires manual configuration for each transaction.

HIFO (Highest In First Out) is a variant of specific identification that always selects the parcel with the highest cost base, minimising the capital gain on each disposal. HIFO is not an automatic ATO-approved method; it is an application of specific identification where the selection rule happens to be choosing the highest-cost parcel. The same record-keeping and contemporaneous documentation requirements apply.

 

A Worked Example: The Same Sale Under Three Methods

The difference between methods is easier to see with numbers than with description. The following is a simplified illustration using round figures, not a recommendation, and it ignores fees so the arithmetic stays visible.

Assume an investor made three purchases of the same asset, each of 1 unit:

• Parcel A, bought March 2023 for AUD 20,000
• Parcel B, bought November 2024 for AUD 60,000
• Parcel C, bought February 2026 for AUD 90,000

In June 2026 they sell 1 unit for AUD 100,000. Which parcel was sold depends entirely on the method applied.

Under FIFO, Parcel A is treated as sold. The cost base is AUD 20,000 and the gross capital gain is AUD 80,000. Parcel A was held for more than 12 months, so the 50% CGT discount is available, bringing the net capital gain to AUD 40,000.

Under LIFO, Parcel C is treated as sold. The cost base is AUD 90,000 and the gross gain is AUD 10,000. Parcel C was acquired in February 2026 and sold in June 2026, so it was held for less than 12 months and no discount applies. The net capital gain is AUD 10,000.

Under specific identification selecting the highest cost parcel, the investor also nominates Parcel C, producing the same AUD 10,000 gain, but does so as a documented choice made at the time of disposal rather than as an automatic ordering rule.

Two things in that example are worth sitting with. The gross gains differ by AUD 70,000 on an identical sale. And the smallest gross gain is not automatically the best outcome, because the 50% discount on a parcel held over 12 months can outweigh a smaller gain on a parcel held under 12 months. In this example it does not, and by a wide margin: AUD 40,000 net against AUD 10,000. Shift the acquisition dates by a few months and the ranking flips, which is why the method is worth modelling against your own parcel history rather than defaulting into.

There is also a consequence beyond this year. Selling Parcel C leaves Parcels A and B still held, so the low-cost parcel remains in the portfolio and its gain is deferred rather than avoided. Selling Parcel A under FIFO clears the largest embedded gain out of the portfolio now. Which is preferable depends on what the investor plans to do next, which is exactly why this is a decision to model rather than default into.

ATO Requirements for Cost Basis Consistency

The ATO requires that you apply the same cost basis method consistently throughout a financial year and maintain that method in subsequent years unless there is a substantive reason to change. This means you cannot use FIFO for some disposals and LIFO for others within the same year to cherry-pick favourable outcomes.

Method changes between financial years may be acceptable if there is a genuine reason (such as a court ruling, new ATO guidance, or a change in circumstances), but should be disclosed in the tax return and supported by documentation. Tax agencies globally are increasing their scrutiny of method switching around volatile crypto markets.

Maintaining detailed crypto tax records is the foundation for applying any cost basis method correctly. Records must include the date of acquisition, the AUD value at acquisition (not just the token amount), the acquisition fees paid, and the date and value of each disposal. Using the best crypto tax calculator available to Australian investors keeps these records structured and audit-ready.

 

Do Parcels Pool Across Wallets and Exchanges?

This is the question most investors actually arrive with, and it changes the answer the methods produce.

The cost basis question is about the asset, not about where it happens to be sitting. If you hold the same cryptocurrency across two exchanges and a hardware wallet, those holdings are not three separate tax positions that each run their own independent FIFO queue. Moving crypto between wallets you own is not itself a disposal, so a transfer does not create a new parcel or reset an acquisition date; the original parcel and its original cost base travel with it.

The practical consequence is that a per-exchange view of your records will not reconcile. An exchange only sees the parcels that passed through it, so its reporting reflects a partial history and can produce a very different figure from a correctly consolidated one.

This is where most Australian crypto tax work actually goes: assembling one consolidated transaction history across every venue and wallet, then applying a single consistent method to it. Our guides on crypto tax across multiple wallets and exchanges and what to do when transaction history is missing cover the reconstruction problem, and reporting a large number of transactions covers what happens when the history is long.

Because the reconciliation is the hard part rather than the arithmetic, this is the area where dedicated software and a crypto-experienced accountant earn their cost most clearly.

Practical Guidance for Australian Investors

For most Australian crypto investors using a dollar-cost averaging strategy to build a position over time, FIFO is the safest and most defensible starting point because it aligns with ATO defaults and is well-understood by tax agents. For investors with complex portfolio histories who have made many purchases at varying prices, engaging a specialist to model the outcomes under different methods before filing is worthwhile.

The ATO data matching program means the ATO already has data from major exchanges about your transaction history. The method you apply must produce results consistent with your actual transaction history: you cannot use a method that produces implausible results relative to the record the ATO holds from exchange data sharing.

Regardless of method chosen, the absolute requirement is accurate records. The crypto tax record-keeping guide covers what to keep and how. The ATO crypto tax overview provides the regulatory framework. And the is crypto tax free in Australia guide clarifies which situations may involve no tax liability under the personal use asset exemption.

This article is for educational purposes only and does not constitute financial or tax advice. Australian crypto tax law is complex and subject to change; consult a registered tax agent or accountant regarding your specific circumstances before making any decisions.

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