First In First Out Method vs Specific Identification for Shares

Table of Contents

1. Introduction: Why Parcel-Level Lot Selection Matters
2. Understanding Parcel-Level Lots and Inventory Costing
3. FIFO Method: First In, First Out Explained
4. LIFO Method: Last In, First Out Explained
5. Specific Identification: The Precision Approach
6. Highest-Cost-First Method: An Australian Tax Strategy
7. Comparing Methods: Tax Outcomes and Trade-Offs
8. How to Implement Parcel-Level Lot Selection in Your Portfolio
9. Common Mistakes and How to Avoid Them
10. Summary and Next Steps

Introduction: Why Parcel-Level Lot Selection Matters

FIFO vs specific identification comes down to simplicity versus control. Where a holding of identical shares cannot be distinguished, TD 33 leaves the decision to you: the Commissioner has accepted first-in-first-out as a reasonable basis of identification and will also accept your own selection, so FIFO is an accepted basis there rather than an automatic rule. FIFO applies the oldest parcel first; specific identification nominates the parcel or parcels sold, which can tailor capital gains outcomes but needs records adequate to support the decision you made.

Parcel-level lot selection refers to the method you use to determine which units or shares you’re disposing of when you make a sale. If you’ve purchased the same stock multiple times at different prices, you have parcels (or lots) with different cost bases. The method you choose to identify which parcel you’re selling can dramatically affect your capital gains tax (CGT) liability. For the arithmetic behind each outcome, see how CGT is calculated on ASX trades.

For example, imagine you own 1,000 shares of a major ASX bank. You bought 300 shares at $50 in 2019, another 400 at $60 in 2021, and 300 at $70 in 2023. When you sell 500 shares at $80 today, which parcel are you selling? Are you selling the oldest shares first (FIFO), the newest (LIFO), or a specific combination? Your answer determines whether you realize a $15,000 gain or a $5,000 gain—a $10,000 difference in taxable income.

Understanding parcel level lots helps you see exactly why the same sale can have very different tax outcomes depending on which parcels are chosen. Choosing among parcel level lots is effectively a pre-trade tax decision that should be part of your investment process. This is why parcel-level lot selection is not just an accounting technicality; it’s a core tax-planning tool. Under ATO Taxation Determination TD 33, shares you can individually distinguish are identified as a matter of fact — their acquisition date and cost base are not a choice. A choice arises only where the parcels form part of a holding of identical shares that cannot be distinguished: there you decide which shares were disposed of, and keep records adequate to support that decision. The Commissioner has accepted first-in-first-out as a reasonable basis of identification in that situation, and will also accept your own selection — so FIFO is an accepted basis, never an automatic rule. FIFO and LIFO below describe which parcel you end up nominating; they are not separate elections you register with the ATO. Understanding these methods—and knowing which to apply in your circumstances—puts the tax cost inside your trading decision, rather than discovering it at tax time.

Understanding Parcel-Level Lots and Inventory Costing

Before diving into specific methods, it’s essential to understand what a “parcel” or “lot” actually is and why the concept matters in the Australian investment context.

What Is a Parcel or Lot?

A parcel (also called a lot) is a discrete purchase of shares or units. Each parcel has:

• Acquisition date: when you bought it
• Quantity: how many units
• Cost base: the price per unit (plus transaction costs like brokerage)
• Total cost: quantity × cost base

When you hold multiple parcels of the same security, you have a choice about which parcel to sell when you dispose of part of your holding. This choice is the essence of parcel-level lot selection.

Recordkeeping for parcel level lots is the backbone of any claim you make to the ATO about which parcels were sold. Treat parcel level lots as separate mini-investments inside a single holding — each has its own performance and tax profile. Because the tax outcome depends on the cost base of the parcel you choose, thinking in terms of parcel level lots helps you align trading with your tax goals. What the ATO actually requires is that your records let you identify the parcel you sold; there is no method you elect or register, and no approval process to go through. Where the parcels cannot be distinguished, TD 33 leaves the decision with you, and both your own selection and a first-in-first-out basis are accepted. Without records supporting a selection, first-in-first-out is the basis that remains.

Why Inventory Costing Methods Apply to Share Trading

Inventory costing methods—such as FIFO, LIFO, and specific identification—originated in manufacturing and retail to track the cost of goods sold. However, the same logic applies to share trading. When you hold multiple parcels, you must decide which parcel leaves your inventory (your portfolio) when you sell.

The parallel is useful for describing the mechanics, but the Australian tax treatment is not an inventory election. Taxation Determination TD 33 works differently again: shares that can be individually distinguished are identified as a matter of fact, and where a holding of identical shares cannot be distinguished the decision is yours — the Commissioner accepts first-in-first-out as a reasonable basis of identification and will equally accept your own selection, so neither is a fallback from the other. So "choosing FIFO" or "choosing LIFO" is shorthand for which parcel you nominate — not a method you lodge with the ATO.

The Role of Cost Base in CGT Calculations

Your cost base is the amount you paid to acquire a share, including incidental costs like brokerage, and adjusted for corporate actions (dividends reinvested, share splits, etc.). When you sell, your capital gain is:

Capital Gain = Sale Price − Cost Base

If you have multiple parcels with different cost bases, the parcel-level method you choose determines which cost base applies to your sale, and therefore your tax outcome. Each parcel level lots entry will therefore produce a different capital gain calculation depending on whether the parcel had a low or high cost base. Properly tracking parcel level lots ensures you don’t overpay tax by accidentally attributing sales to the wrong parcels.

Averaging cost bases is generally not permitted. TD 33 (paragraph 5) allows an average cost only where the shares are in the same company, were acquired on the same day, and confer identical rights and impose identical obligations. Any share for which a market value is deemed to be the cost of acquisition has to be left out of the average. Outside that narrow case, work parcel by parcel.

What is the FIFO method for shares?

How FIFO Works

FIFO (First In, First Out) assumes that the shares you bought first are the shares you sell first. When you dispose of shares, the cost base used is that of the oldest parcel(s) until they are exhausted, then the next-oldest parcel, and so on.

FIFO Example:

• January 2020: Buy 200 shares at $50 = $10,000 cost base
• June 2021: Buy 300 shares at $60 = $18,000 cost base
• March 2023: Buy 200 shares at $75 = $15,000 cost base
• Total holding: 700 shares

In September 2024, you sell 400 shares at $85 each = $34,000 proceeds.

Under FIFO:

• First 200 shares sold use the January 2020 parcel: $50 cost base → $7,000 gain (200 × $35)
• Next 200 shares sold use the June 2021 parcel: $60 cost base → $5,000 gain (200 × $25)
• Total gain: $12,000

Under FIFO, the treatment of parcel level lots is straightforward — the oldest parcel level lots are consumed first. If your goal is simplicity and low compliance overhead, applying FIFO across your parcel level lots may be the right choice. Many investors default to FIFO because it reduces record-keeping complexity around parcel level lots.

Advantages of FIFO

1. Simplicity: FIFO is the easiest method to track and explain, especially if you don’t maintain detailed parcel records. Many brokers default to FIFO.
2. An Accepted Basis: Where a holding of identical shares cannot be distinguished, the Commissioner has accepted first-in-first-out as a reasonable basis of identification (TD 33, paragraph 4). That is acceptance of the basis itself — not an assurance about how closely any particular return is reviewed.
3. Consistency: FIFO is intuitive—it mirrors the natural flow of inventory in many businesses.
4. Reduced Compliance Risk: Because it’s straightforward, there’s less risk of error or ATO challenge.

Disadvantages of FIFO

1. Larger Gross Gains in Rising Markets: In a bull market, applying FIFO matches the sale to your oldest (usually lowest-cost) parcel, which maximises the gross gain. Nothing compels that outcome — where your parcels cannot be distinguished the Commissioner will also accept your own selection — and the oldest parcels are the ones most likely to have passed the 12-month mark, so compare after-discount figures rather than gross gains.
2. No Tailoring Once Applied: A FIFO result is fixed by purchase order, so it cannot be shaped around your current tax situation (e.g., offsetting a loss in another holding).
3. No Loss Harvesting Opportunity: If you want to realize a loss to offset other gains, FIFO may force you to sell a gain parcel instead.

When FIFO Makes Sense

FIFO is appropriate when:

• You’re a long-term buy-and-hold investor with infrequent trades.
• Your oldest shares have appreciated significantly, and you’re comfortable with the tax outcome.
• You prefer simplicity over tax optimization.
• You’re trading in a declining market, where older parcels may have losses.

Which share parcels should you sell first?

How LIFO Works

LIFO (Last In, First Out) assumes that the most recently purchased shares are the first to be sold. When you dispose of shares, the cost base used is that of the newest parcel(s) until they are exhausted, then the next-newest parcel, and so on.

LIFO Example (same scenario as FIFO):

In September 2024, you sell 400 shares at $85 each = $34,000 proceeds.

Under LIFO:

• First 200 shares sold use the March 2023 parcel: $75 cost base → $2,000 gain (200 × $10)
• Next 200 shares sold use the June 2021 parcel: $60 cost base → $5,000 gain (200 × $25)
• Total gain: $7,000

Using LIFO on parcel level lots requires careful contemporaneous documentation so the ATO can see which parcels were intended to be sold. Because parcel level lots under LIFO are consumed in reverse chronological order, the tax impact can be materially different compared to FIFO. There is no LIFO election to make: your records simply have to show that the newest parcel is the one you identified at the time of sale.

Advantages of LIFO

1. Tax Efficiency in Rising Markets: LIFO allows you to sell newer (typically higher-cost) parcels first, deferring gains on older, lower-cost parcels. This reduces your current-year CGT.
2. Flexibility for Tax Planning: LIFO can be strategically used to manage your tax bracket or offset losses.
3. Defers Gains: By selling higher-cost parcels, you defer the realization of gains on lower-cost parcels, allowing them to compound longer.

Disadvantages of LIFO

1. It Stands or Falls on Your Records: Because LIFO is not an election, the only thing supporting it is your contemporaneous identification of the newest parcel. Without that, first-in-first-out is the basis that remains, and your tax plan disappears.
2. Complexity: Tracking LIFO requires detailed parcel records and careful documentation.
3. Selling Newest Parcels Often Forfeits the Discount: Recently acquired parcels are the ones least likely to have passed the 12-month mark, so a LIFO-shaped sale frequently gives up the 50% CGT discount on the very parcels it disposes of.
4. Not Universally Supported by Brokers: Many Australian brokers don’t surface parcel selection at all, making it difficult to implement in practice.

When LIFO Makes Sense (With Caution)

LIFO is rarely the default choice for Australian investors, but it may be justified when:

• You’re in a high tax bracket and want to minimize current-year CGT.
• You have detailed parcel records and can document your method.
• You’re prepared to defend your choice to the ATO with a clear tax strategy.
• You’re harvesting losses and want to offset them with smaller gains.

Important: There is nothing here to "adopt". Selling on a LIFO pattern simply means specifically identifying your newest parcel on each disposal, and it holds up only if you identified that parcel at the time of the trade and kept the evidence. Check the acquisition date on the parcel before you nominate it — the newest parcel is also the one most likely to be short of 12 months — and consult an accountant if the amounts are material.

How does specific identification work for shares?

How Specific Identification Works

Specific identification (also called the “specific lot” method) allows you to explicitly nominate which parcel(s) you are selling at the time of disposal. Instead of following a predetermined sequence (as with FIFO or LIFO), you identify the exact shares you wish to sell by reference to their acquisition date, cost base, and quantity.

To use specific identification, you must:

1. Maintain detailed records of each parcel (acquisition date, quantity, cost base).
2. Identify the parcel you’re selling at the time of the trade (not later).
3. Document your choice with your broker or record-keeper (e.g., in a trade confirmation or instruction).
4. Keep evidence of your identification for ATO audit purposes.

Specific Identification Example (same scenario):

In September 2024, you sell 400 shares at $85 each = $34,000 proceeds.

You specifically identify:

• 200 shares from the June 2021 parcel: $60 cost base → $5,000 gain (200 × $25)
• 200 shares from the January 2020 parcel: $50 cost base → $7,000 gain (200 × $35)
• Total gain: $12,000

Alternatively, you could identify:

• 400 shares from the March 2023 parcel: $75 cost base → $4,000 gain (400 × $10)
• Total gain: $4,000

The outcome depends entirely on your choice. Specific identification of parcel level lots gives you the most precise control over your tax outcome because each parcel level lots decision directly alters the cost base applied to the sale. When you use specific identification, make sure each parcel level lots choice is captured in writing at the time of trade.

How Specific Identification Differs from FIFO and LIFO

Unlike FIFO and LIFO, which follow a rigid sequence, specific identification gives you complete control. You decide which parcels to sell based on your tax situation, investment goals, and portfolio strategy. This flexibility is powerful, but it comes with responsibility: you must document your choice and be prepared to defend it.

Advantages of Specific Identification

1. Maximum Tax Efficiency: You can tailor your disposal to your exact tax situation, whether you want to minimize gains, harvest losses, or manage your tax bracket.
2. An Accepted Basis: The Commissioner will accept your own selection of the shares disposed of (TD 33, paragraph 4), provided your records are adequate to support that decision. There is no form to lodge and no procedure to register — the records are the requirement.
3. Strategic Flexibility: You can use specific identification to implement tax-loss harvesting, rebalance your portfolio efficiently, or manage concentrated positions.
4. Precision: You know exactly which shares you’re selling and why.

Disadvantages of Specific Identification

1. Documentation Burden: You must maintain detailed records and provide evidence of your identification at the time of sale.
2. Broker Cooperation: Not all brokers support specific identification. You may need to maintain your own records or use a portfolio tracker that supports parcel-level tracking.
3. Complexity: Requires more administrative effort than FIFO.
4. Risk of Error: If you cannot show which parcel you identified at the time of sale, first-in-first-out is the basis that remains — which may undo the outcome you were planning for.

When Specific Identification Makes Sense

Specific identification is ideal when:

• You want to optimize your tax outcome on a trade-by-trade basis.
• You’re harvesting losses to offset gains elsewhere in your portfolio.
• You hold concentrated positions and want to manage your tax liability strategically.
• You have detailed parcel records and use a broker or portfolio tracker that supports specific identification.
• You’re rebalancing your portfolio and want to minimize the tax cost of the rebalancing.

Highest-Cost-First Method: An Australian Tax Strategy

How Highest-Cost-First Works

Highest-cost-first is a variant of specific identification where you prioritize selling shares with the highest cost base. This method minimizes your capital gain (or maximizes your capital loss) on each trade.

Highest-Cost-First Example (same scenario):

In September 2024, you sell 400 shares at $85 each = $34,000 proceeds.

Under highest-cost-first:

• First 200 shares sold use the March 2023 parcel: $75 cost base → $2,000 gain (200 × $10)
• Next 200 shares sold use the June 2021 parcel: $60 cost base → $5,000 gain (200 × $25)
• Total gain: $7,000

Highest-cost-first applied to parcel level lots focuses on realizing the smallest possible gain (or largest loss) in the current year. By intentionally choosing higher-cost parcel level lots, you can reduce taxable income without unnecessarily liquidating your best-performing holdings. When you apply highest-cost-first, be sure to record which parcel level lots were sold and why to create an audit trail.

Why Highest-Cost-First Is Popular in Australia

Highest-cost-first is often the default recommendation for Australian investors because it:

1. Minimizes Current-Year CGT: By selling high-cost parcels first, you reduce your taxable gain in the current year.
2. Preserves Low-Cost Parcels: Your oldest, most appreciated parcels remain in your portfolio to compound longer.
3. Aligns with Tax Planning: It supports a tax-efficient rebalancing strategy, and because it is only a rule for deciding which parcel you nominate, it rests on the same TD 33 footing as any other selection — your records.
4. Supports Loss Harvesting: If you want to realize a loss, highest-cost-first ensures you harvest the maximum loss possible.

Advantages of Highest-Cost-First

1. Tax Efficiency: Reduces your taxable capital gain in the current year.
2. An Accepted Basis: "Highest cost first" is not a separate method — it is a rule for choosing which parcel to nominate, and the Commissioner accepts the taxpayer’s selection where the records support it (TD 33, paragraph 4).
3. Simplicity: Easier to explain and defend than LIFO.
4. Aligns with Tax Planning Goals: Supports deferral of gains on your most appreciated holdings.

Disadvantages of Highest-Cost-First

1. May Not Suit All Situations: If you’re in a loss position or want to realize gains for other reasons, highest-cost-first may not be optimal.
2. Still Requires Documentation: You must record your choice and maintain evidence.
3. Broker Support: Not all brokers support highest-cost-first; you may need to use a dedicated portfolio tracker.

When Highest-Cost-First Makes Sense

Highest-cost-first is appropriate when:

• You’re rebalancing your portfolio and want to minimize the tax cost.
• You hold multiple parcels of the same security and want a simple, tax-efficient rule.
• You’re in a high tax bracket and want to defer gains.
• You want a simple, consistent rule for which parcel to nominate, backed by the records TD 33 asks for.

Comparing Methods: Tax Outcomes and Trade-Offs

Side-by-Side Comparison

Let’s compare the tax outcomes of all four methods using our ongoing example:

Key Observations:

1. FIFO produces the highest tax: $12,000 in gains, resulting in up to $5,400 in tax at the top marginal rate.
2. Specific identification offers the most control: You could minimize gains to just $4,000 by choosing the highest-cost parcels.
3. LIFO and highest-cost-first are equivalent in this scenario, both producing $7,000 in gains.
4. The difference is material: Between FIFO and optimal specific identification, you could save $3,600 in tax on a single trade.

Comparing parcel level lots outcomes across methods highlights how the same number of shares sold can produce wildly different tax bills. Analysts who model parcel level lots across multiple years can identify the compounding tax impact of consistently using one method versus another. When choosing a method, think about long-term consequences for your parcel level lots, not just the single transaction.

The 50% CGT Discount and the 12-Month Test

The table above compares gains, not tax bills. Before acting on it, apply the 50% CGT discount: an individual who has held a parcel for more than 12 months includes only half of the gain on that parcel in assessable income. In the running example every parcel — January 2020, June 2021 and March 2023 — was acquired more than 12 months before the September 2024 sale, so each tax figure in the table halves. FIFO’s $5,400 at the top marginal rate becomes $2,700, and the optimal specific identification becomes $900.

The discount applies parcel by parcel, which is exactly why it can invert your ranking. Take three parcels of the same stock, with a 39% marginal rate in mind:

• Parcel A: $6,000 gain, held 2 years → $6,000 × 50% × 39% = $1,170
• Parcel B: $4,000 gain, held 12 months and a day → $4,000 × 50% × 39% = $780
• Parcel C: $2,000 gain, held 3 months → $2,000 × 100% × 39% = $780

Parcel C has the smallest gain of the three and still costs exactly as much tax as Parcel B, which carries double the gain, because Parcel C is short of 12 months and attracts no discount. A highest-cost-first rule applied blindly would have picked Parcel C. This is the most common way a parcel choice that looks tax-efficient quietly costs money.

The practical consequence: check the acquisition date before you nominate a parcel, not just its cost base. If a parcel is within a few weeks of its 12-month anniversary and nothing forces you to sell today, waiting until it crosses the line is often worth more than any cost-base optimisation available to you now. Losses work the other way — there is no holding-period test on a capital loss, so a loss parcel can be harvested at any age.

Factors Affecting Your Choice

1. Your Tax Bracket: Higher earners benefit more from minimizing gains.
2. Portfolio Composition: If you hold many parcels of the same security, specific identification becomes more valuable.
3. Trading Frequency: Frequent traders benefit more from a flexible method like specific identification.
4. Broker Support: Your broker’s capabilities may constrain your options.
5. Compliance Comfort: Some investors prefer the simplicity of FIFO over the documentation burden of specific identification.
6. Overall Tax Strategy: Consider your total tax position, including losses elsewhere in your portfolio.

The Role of Tax-Loss Harvesting

Parcel-level lot selection is especially powerful when combined with tax-loss harvesting. If you hold a security that has declined in value, you can use specific identification to sell the highest-cost parcels first, realizing a loss to offset gains elsewhere. This is a core tax-planning strategy for Australian investors.

For example, if one of your parcels has a loss (cost base $80, current value $60), you can specifically identify that parcel for sale, realizing a $20-per-share loss. This loss can then offset capital gains from other trades, reducing your overall CGT liability. A net capital loss cannot be applied against your salary or other ordinary income — it is carried forward indefinitely until you have capital gains to absorb it.

Blended Selection: Splitting One Sale Across Parcels

Nothing requires a single disposal to come out of a single parcel. Because you are identifying parcels rather than applying a percentage, you can split one sell order across several and land on an outcome that no single-parcel rule would produce.

Suppose you need to sell 500 shares and hold:

• Parcel A: 300 shares carrying a $6,000 gain ($20 per share)
• Parcel B: 400 shares carrying a $2,000 gain ($5 per share)
• Parcel C: 300 shares carrying a $500 loss ($1.67 per share)

All of Parcel A plus 200 of Parcel B realises $6,000 + $1,000 = $7,000. All of Parcel A plus 200 of Parcel C realises $6,000 − $333 = $5,667. Two hundred of Parcel B plus all of Parcel C realises $1,000 − $500 = $500. Every one of those satisfies the same 500-share rebalancing instruction.

Blending earns its keep when you are managing to a number rather than to a minimum: holding your total realised gain under a ceiling you set for the year, consuming a carried-forward capital loss exactly, or splitting a large disposal across two financial years. It needs either a broker that will accept a multi-parcel instruction or your own contemporaneous record of the split — and each parcel in the blend still has to be checked against the 12-month test above.

How to Implement Parcel-Level Lot Selection in Your Portfolio

Step 1: Choose a Portfolio Tracker That Supports Parcel-Level Selection

Not all brokers or portfolio trackers support parcel-level lot selection. Crowdfolio is an Australian portfolio tracker specifically designed for tax-aware investors, allowing you to preview parcel-level outcomes under the four methods it compares (minimise-tax, FIFO, LIFO and highest-cost-first) before you trade. This upfront forecasting puts the tax cost inside your trading decision.

Other options include:

• Sharesight: Supports FIFO and specific identification but requires manual entry.
• Navexa: Offers parcel-level tracking and CGT forecasting.
• Your broker’s native tools: CommSec, Stake, and others may support specific identification, but typically with limited flexibility.

When evaluating tools, ensure they can import and manage parcel level lots accurately so you can simulate different tax outcomes across potential trades. Use a tracker that highlights parcel level lots exposures and shows the tax impact of selling each parcel.

Step 2: Maintain Detailed Parcel Records

For any method beyond FIFO, you must maintain records showing:

• Acquisition date of each parcel
• Quantity purchased
• Price per unit (cost base)
• Total cost (including brokerage and other incidental costs)
• Corporate actions (dividends reinvested, share splits, etc.)
• Disposal date and method (which parcel was sold and why)

Keep these records for at least 5 years (the ATO’s standard record-retention period).

Accurate parcel level lots records are not optional — they are essential evidence if the ATO queries a specific identification or highest-cost-first choice.

Step 3: Document Your Method Choice

There is no method to adopt with the ATO, but a default rule of your own is worth writing down. For example:

• “For XYZ Ltd, I will use the highest-cost-first method to minimize capital gains.”
• “For ABC ETF, I will use specific identification to optimize rebalancing outcomes.”

That note, together with your parcel records, is what supports the identification if the ATO queries a disposal later.

Step 4: Identify Parcels at the Time of Sale

When you execute a trade, explicitly identify which parcel(s) you’re selling. If using Crowdfolio, you can preview the tax outcome for each method before you trade, then instruct your broker accordingly.

For example, you might email your broker: “Sell 500 shares of XYZ Ltd. Specifically identify the 300 shares purchased on 15 June 2021 at $60, and the 200 shares purchased on 10 March 2023 at $75.”

In practice there are three ways this gets recorded, in descending order of evidentiary strength:

• Identify at trade time. Some Australian brokers let you tag the specific purchase lot on the sell order itself. This is the strongest record available, because the identification and the disposal carry the same timestamp.
• Instruct in writing immediately after. If your broker only sells "shares", send the instruction anyway — trade reference, quantity, and the acquisition date and price of each parcel you want matched — and keep the sent copy. Do it the same day, not at tax time.
• Record it in your tracker. A portfolio tracker that time-stamps the parcel you designated gives you a dated record even where the broker never sees it. It is the weakest of the three on its own, but it is what most DIY investors actually have, and it beats reconstructing your intent a year later.

Make sure the instruction clearly ties to the parcel level lots you hold so the broker and your records align.

Step 5: Reconcile and Report

After each trade, reconcile your portfolio records with your broker statements. At year-end, prepare a CGT schedule showing:

• Each disposal (date, quantity, proceeds)
• The parcel(s) sold (acquisition date, cost base)
• The method used
• The capital gain or loss

Provide this schedule to your accountant for inclusion in your tax return. Crowdfolio generates accountant-ready reports that simplify this process.

Step 6: Monitor for Part IVA and Wash-Sale Risks

While parcel-level selection is a legitimate tax-planning tool, be aware of anti-avoidance rules:

• Part IVA: The ATO may challenge aggressive tax-planning arrangements under Part IVA of the Income Tax Assessment Act 1936. If your parcel selection appears designed primarily to avoid tax (rather than for legitimate investment reasons), the ATO may disallow the benefit.
• Wash sales: Australia has no codified wash-sale rule of the US kind. Selling at a loss and buying straight back is assessed under Part IVA instead — if the disposal and repurchase leave your economic position unchanged and the loss looks like the point of the exercise, the ATO can cancel the benefit. The test is purpose and substance, not a fixed number of days.

A portfolio tracker like Crowdfolio flags these risks upfront, leaving the judgement to you.

Common Mistakes and How to Avoid Them

Mistake 1: Failing to Document Parcel Selection

The Problem: You use specific identification or highest-cost-first but don’t document which parcel you sold or why.

The Risk: If the ATO reviews your return, you cannot show which parcel you identified. First-in-first-out is then the basis that remains, which may increase your tax liability.

How to Avoid It: Always document your parcel selection in writing at the time of the trade. Keep emails to your broker, trade confirmations, and portfolio tracker records. Treat each trade as a parcel level lots decision that needs supporting evidence.

Mistake 2: Changing Methods Without Justification

The Problem: You use FIFO one year, then switch to specific identification the next year without a clear reason.

The Risk: Switching with no investment reason behind it is harder to defend, because it leaves each identification looking driven by the tax outcome alone rather than by your records and your strategy.

How to Avoid It: There is no approval to seek, but there is a pattern to avoid. Decide on a default rule, write it down, and let each departure from it be driven by a documented investment reason rather than by whichever parcel happens to be cheapest that day. Consistency is what makes each individual identification credible.

Mistake 3: Confusing Parcel-Level Selection with Tax-Loss Harvesting

The Problem: You use specific identification to realize a loss, then immediately repurchase the same security, so nothing about your economic position has actually changed.

The Risk: The ATO may cancel the benefit of the loss under Part IVA, and penalties can follow.

How to Avoid It: There is no 30-day bright line in Australia to shelter behind — Part IVA asks whether anything real changed. If you want the loss, make the disposal a genuine investment decision: exit the position, or move to a different (not substantially the same) exposure and leave a meaningful gap before considering re-entry. Selling and buying back the same ticker on the same day is the pattern the ATO has publicly warned about.

Mistake 4: Not Accounting for Corporate Actions

The Problem: You hold shares that undergo a capital return, share split, or dividend reinvestment. You don’t adjust your cost base or parcel records accordingly.

The Risk: Your cost base is incorrect, leading to an incorrect capital gain or loss calculation.

How to Avoid It: After any corporate action, update your parcel records to reflect the adjusted cost base and quantity. A portfolio tracker handles this automatically, keeping your parcel level lots accurate.

Mistake 5: Relying Solely on Broker Defaults

The Problem: Your broker defaults to FIFO, and you assume that’s the best method for your situation.

The Risk: You miss opportunities for tax-efficient rebalancing or loss harvesting.

How to Avoid It: Actively choose your parcel-level method based on your tax situation and investment goals. Use a portfolio tracker to preview outcomes before you trade, and ensure your parcel level lots choices are recorded.

Mistake 6: Ignoring Part IVA Risks

The Problem: You use specific identification to minimize your CGT, but the ATO views your arrangement as a tax-avoidance scheme.

The Risk: The ATO disallows the benefit under Part IVA and assesses you for the additional tax, plus penalties.

How to Avoid It: Ensure your parcel selection has a genuine investment purpose, not solely a tax purpose. Document your investment rationale. If you’re uncertain, consult an accountant.

A recurring error is mislabeling parcel level lots when importing historical trades — this can distort all downstream calculations. Always verify the parcel level lots against original broker confirmations after migrations or bulk imports.

Summary and Next Steps

Key Takeaways

1. Parcel-level lot selection is a powerful tax-planning tool that allows you to optimize your capital gains tax outcome on a trade-by-trade basis.
2. FIFO is the simplest method but often the least tax-efficient in rising markets. It’s the default for many brokers and requires minimal documentation.
3. LIFO minimizes current-year gains but it is not a separate election — it is specific identification pointed at your newest parcel, and those parcels are the ones most likely to miss the 12-month discount. Use it only with contemporaneous records and professional advice.
4. Specific identification offers maximum flexibility, allowing you to tailor your disposal to your exact tax situation. It requires detailed documentation but is worth the effort for active traders and portfolio rebalancers.
5. Highest-cost-first is a practical compromise, minimizing gains while resting on the same records-based footing as any other selection. It’s ideal for Australian investors seeking tax efficiency without excessive complexity.
6. The 50% CGT discount can outrank the cost base: a parcel held more than 12 months has only half its gain assessed, so the cheapest parcel to sell is often not the one with the highest cost base. Check the acquisition date first.
7. Documentation is critical regardless of the method you choose. Keep detailed records of each parcel, your method choice, and your identification at the time of sale.
8. Parcel-level selection must align with your overall tax strategy, including tax-loss harvesting, wash-sale avoidance, and Part IVA compliance.

Parcel level lots should be regarded as strategic levers in your broader investment plan rather than as ad-hoc accounting choices. Start treating parcel level lots decisions as part of every sell instruction to ensure tax outcomes align with your goals.

Implementing Your Strategy

To get started:

1. Audit your current holdings: List each security you own, the parcels you hold (acquisition date, cost base, quantity), and the current value. Identify opportunities for tax-efficient rebalancing.
2. Choose your method: Based on your tax bracket, trading frequency, and portfolio composition, decide which parcel-level method is right for each security.
3. Select a portfolio tracker: Use a tool like Crowdfolio that supports parcel-level tracking and CGT forecasting. This allows you to preview tax outcomes before you trade, putting the tax cost inside your decision.
4. Document your approach: Write down your method choice for each security and your investment rationale. Keep this documentation with your tax records.
5. Execute with precision: When you trade, explicitly identify the parcel(s) you’re selling. Use your portfolio tracker to confirm the tax outcome.
6. Review annually: At year-end, reconcile your records and prepare a CGT schedule for your accountant. Review your method choices and adjust if your circumstances have changed.

When to Seek Professional Advice

Consider consulting an accountant or tax adviser if:

• You hold a concentrated position or significant unrealized gains.
• You’re planning a major portfolio rebalance.
• Your tax situation is complex (e.g., you have losses in other areas to offset).
• You’re uncertain about Part IVA or wash-sale implications.
• You want to implement a sophisticated tax-loss harvesting strategy.

The Bottom Line

Parcel-level lot selection is not just an accounting detail—it’s a core component of tax-efficient investing for Australian DIY investors. By understanding FIFO, LIFO, specific identification, and highest-cost-first methods, you can take control of your capital gains tax outcome and optimize your portfolio for long-term wealth creation.

The key is to make these decisions before you trade, not after. Tools like Crowdfolio make this possible, allowing you to forecast parcel-level tax outcomes and incorporate them into your trading decisions. Combined with disciplined record-keeping and professional advice when needed, parcel-level lot selection can save you thousands in capital gains tax over your investing lifetime.

Start today: review your current holdings, choose your method, and commit to documenting your approach. Your future self—and your accountant—will thank you. Treat every sale as an opportunity to manage the tax impact of your parcel level lots and reap the long-term benefits.