Wash sale rules and retiree tax-loss harvesting: Part IVA risk when crystallising losses on assets you intend to repurchase

For Australian retirees managing personal share portfolios outside super, tax-loss harvesting — selling positions at a loss to offset realised capital gains elsewhere — is a standard year-end tax planning strategy that can produce material savings (losses are applied before the CGT discount under section 102-5 of the Income Tax Assessment Act 1997, magnifying their tax value). However, where the strategy involves repurchasing the same or substantially identical asset within a short period of the loss-crystallising sale, the general anti-avoidance provisions in Part IVA of the Income Tax Assessment Act 1936 (sections 177A and following) and the ATO's Taxation Ruling TR 2008/1 create a specific risk: the arrangement may be characterised as having the dominant purpose of obtaining a tax benefit with no real change in economic position, leading to the ATO denying the loss under Part IVA's dominant-purpose test in section 177D. There is no legally prescribed safe-harbour period in the Australian wash sale framework — practitioners commonly use 30 or 60 days as a working rule but the ATO's actual application depends on overall facts and circumstances, not just the time gap. For retirees managing year-end portfolio reviews, understanding the wash sale framework is essential to capturing legitimate tax-loss benefits without exposing the arrangement to anti-avoidance challenge.

The basic tax-loss harvesting strategy is straightforward. A retiree holds shares or other CGT assets that have declined in value below their cost base. Selling the assets at the loss crystallises the loss for tax purposes — converting an unrealised loss into a realised capital loss that can be offset against realised capital gains in the same year (under the s.102-5 calculation order, losses are applied at full value against gross gains before the CGT discount applies to the net amount, so each $1 of loss can offset $1 of gross gain even though only 50¢ of that gain would have been assessable after discount). Unused losses carry forward indefinitely against future gains, but can't be applied retrospectively or against ordinary income. The tax benefit is the reduction in capital gains tax payable, which can be substantial for retirees with concentrated gains from concentrated holdings (for example a long-held investment property or share parcel). The strategy typically combines with intentional realisation of gains in the same year — selling some winners and some losers together to produce a net taxable gain that's smaller than the gross gain. For most retirees with diversified portfolios at year-end, the question is whether to crystallise particular losses to manage the year's net capital gain position.

The temptation to repurchase is the source of the wash sale issue. Many retirees who want to harvest a tax loss on a specific holding also want to maintain economic exposure to that holding — perhaps because they expect the price to recover, they value the dividend stream, or the holding plays a specific role in the portfolio. The simple way to achieve both objectives is to sell the loss-making asset and immediately repurchase the same asset, capturing the tax loss while preserving the underlying position. From the retiree's perspective, this might seem reasonable — the asset is still in the portfolio, the tax loss is captured, and the only "cost" is brokerage on the round trip. From the ATO's perspective, this is exactly the kind of arrangement that wash sale rules target — the substantive economic position hasn't changed but a tax benefit has been claimed.

The ATO's framework under TR 2008/1 addresses this concern directly. The ruling describes wash sale arrangements as those involving the disposal of an asset by an entity (or an associate) and the acquisition of the same or substantially identical asset by the same entity or an associate, where the arrangement has the dominant purpose of obtaining the tax benefit. The dominant purpose test is the gateway — Part IVA under s.177D requires that obtaining the tax benefit was the principal motivation for the transaction, considered against eight enumerated factors including the manner in which the scheme was entered into, the form and substance, the timing, and the result that would otherwise have been achieved. If commercial reasons (genuine portfolio rebalancing, asset class reallocation, response to changed circumstances) genuinely motivated the disposal and any subsequent acquisition, the arrangement may not be a wash sale even if the same asset is repurchased. If the timing, structure, and circumstances suggest the tax benefit was the central motivator, Part IVA can apply. The consequence of Part IVA application is that the Commissioner can make a determination cancelling the tax benefit — typically, denying the capital loss. The original cost base typically continues to apply to the asset (or a new acquisition), so there's no offsetting "fresh start" benefit either.

The "same or substantially identical" test is the technical breadth point. Same asset is straightforward — identical shares (for example CBA ordinary shares sold and repurchased) clearly qualify. Substantially identical is more nuanced and depends on facts. Two ETFs tracking the same index (for example two different fund managers' ASX 200 ETFs) might be substantially identical. Two different banks' shares (for example CBA and ANZ) — though similar in some respects — typically aren't substantially identical because they're separate companies with different management, operations, and capital structures. Materially different assets — different industry, different asset class, different exposure profile — clearly aren't substantially identical and don't trigger wash sale concern. Sector ETFs as substitutes — selling an individual mining stock and buying a broad mining sector ETF — typically aren't substantially identical because the broader ETF provides exposure to multiple stocks rather than the specific one sold. Repurchase by associates — family member, trust, or company controlled by the taxpayer buying back the asset — can still trigger wash sale concern under Part IVA's reach to associates, even if the original taxpayer doesn't repurchase.

The "30-day rule of thumb" is the most commonly cited safe-harbour but isn't legally prescribed. Many practitioners and advisers use 30 days as a working buffer between sale and repurchase — recommending clients wait at least 30 days before repurchasing the same asset. Some use 60 days for additional safety. The 30-day convention has no statutory basis in Australia (unlike the US, where the IRC has a specific 30-day wash sale rule under §1091) — it's a practical risk management approach rather than a legal threshold. The ATO's actual application of Part IVA looks at the totality of the arrangement: the time gap, the substantial identity of the asset, the dominant purpose, the commercial rationale, and any documentary evidence of the taxpayer's intent. Even with longer gaps (60 or 90 days), if the dominant purpose test is met and the substantive economic position is unchanged, Part IVA can theoretically apply. Conversely, with shorter gaps but genuine commercial reasons (for example the asset was sold for a specific commercial reason and the repurchase happened opportunistically much later), the arrangement may not be a wash sale even with a short time gap.

The alternative strategies for retirees wanting tax-loss benefits while maintaining economic exposure have a specific shape. Similar-but-not-identical replacement. Sell the loss-making asset and buy a different but related asset — different bank, different mining stock, sector ETF rather than individual stock. The replacement provides similar but not identical exposure, defensible as a portfolio rebalancing decision rather than a pure tax play. Sufficient time gap. Wait 30+ days (or longer) between sale and repurchase, using the gap for genuine portfolio review or to fund other purchases. The gap reduces (though doesn't eliminate) wash sale risk. Structural change. Replace direct holding with managed fund or ETF, or change ownership structure (personal to SMSF, individual to family trust) — the changed structure provides commercial substance to the transaction, though the structure change itself may trigger CGT events and stamp duty depending on the asset. Crystallise without repurchase. Sell the loss-making asset and accept the cash position; use the cash for other investments or consumption. Pure tax-loss harvesting with no wash sale risk because there's no repurchase. Offset with intentional gain rather than loss. Realise other gains to offset losses, rather than crystallising specific losses against pre-planned gains. The offset is symmetric and avoids wash sale issues entirely.

The CGT discount interaction is an additional consideration. When a long-held asset is sold to crystallise a loss, the loss is realised at the asset's full negative gain — capital losses don't get the 50% CGT discount that applies to long-held capital gains. Repurchasing the asset resets the holding period for the new acquisition — the 12-month clock for CGT discount eligibility on the eventual disposal restarts. For retirees who have held the asset long enough to qualify for the discount (12+ months) and now repurchase, any subsequent gains within the next 12 months are taxed without discount, with the discount only restored after the new 12-month threshold. The lost discount status on near-term gains is an additional cost of the wash sale strategy that may reduce its net benefit even if Part IVA doesn't apply. For retirees not planning to sell again soon, the discount reset is less material; for those who might sell within 12 months, it's a meaningful cost.

The practical advice work for practitioners advising retirees on year-end tax-loss harvesting has a specific shape. Identify positions with unrealised losses — review the portfolio at year-end (typically May or early June) for assets trading below cost base. Confirm capital gains available for offset — check the year's realised gains and any carried-forward losses. Plan repurchase strategy — decide whether to repurchase, replace with similar-but-different asset, wait for time gap, or accept cash position. Document commercial rationale — for any repurchase, ensure there's documentary evidence of commercial motivation (portfolio review, asset class allocation decision, response to changed market conditions) beyond the tax benefit. Advise on time gap — recommend conservative approach (30+ days minimum), with longer gap where the substantial identity test is closer. Coordinate with broader portfolio rebalancing — tax-loss harvesting integrated with genuine portfolio decisions is more defensible than standalone tax plays. Monitor for ATO guidance changes — interpretation of TR 2008/1 and Part IVA can evolve. Document the advice given — given the anti-avoidance risk, careful documentation of the advice and the client's decisions provides protection for both adviser and client.

What do worked planning examples show?

These two cases show how the wash sale framework plays out for typical retiree scenarios. Illustrative only — not personal advice — using FY25-26 figures.

Case 1 — Robert, 70, retired. Sold investment property in March 2026 for $200k capital gain after CGT discount. Holds CBA shares with $50k unrealised loss; wants to maintain banking sector exposure for dividend income. On these facts, options: (a) Sell CBA shares 28 June, repurchase 5 July — high wash sale risk; the substantively-identical repurchase within a week of disposal makes the dominant-purpose finding straightforward for the ATO. (b) Sell CBA shares 28 June, accept cash position — pure tax-loss harvesting, no wash sale risk, but loses the banking dividend exposure. (c) Sell CBA shares 28 June, buy ANZ shares 5 July — different bank, defensible commercial rationale, low wash sale risk. (d) Sell CBA shares 28 June, buy broad bank or finance sector ETF 5 July — different exposure profile (multiple stocks not just CBA), low risk. (e) Sell CBA shares 28 June, wait until 1 August (35 days) and repurchase CBA — moderate risk due to substantially identical asset despite time gap; the time gap alone doesn't displace the dominant-purpose analysis. Recommendation: option (c) or (d) provides the cleanest combination of tax benefit and continued exposure. The trap to avoid is option (a) — the tax benefit is at material risk under Part IVA.

Case 2 — Margaret, 68, retired. Has $30k carried-forward capital losses from 2023. Wants to crystallise $25k of unrealised gains on long-held BHP shares to use the carried-forward losses, then immediately repurchase BHP to maintain position. On these facts, the structure is the reverse — using losses to offset crystallised gains rather than creating fresh losses. Wash sale concepts technically still relate to Part IVA's dominant-purpose test, though the policy concern is weaker here (no new tax benefit being created, just optimal use of existing carry-forward losses). However, the immediate repurchase still raises questions about the commercial rationale for the round trip. Recommendation: even so, use a similar approach — buy a different mining stock or sector ETF rather than the same BHP shares, or accept a 30-day gap with documented commercial rationale. The same Part IVA test under s.177D applies whether the arrangement is loss harvesting or gain crystallisation. The trap to avoid is assuming Part IVA only applies to loss-creating arrangements — the dominant-purpose test is broader.

For Australian retirees managing personal share portfolios outside super, tax-loss harvesting can produce material tax savings when realised gains and unrealised losses can be offset — but the wash sale rules under Part IVA and TR 2008/1 create a real risk where the same or substantially identical asset is repurchased shortly after the loss-crystallising sale. There's no legally prescribed safe harbour in Australian law; the dominant purpose test in s.177D depends on overall facts and circumstances. Retirees wanting both tax benefit and continued economic exposure have several alternatives: similar-but-not-identical replacements, sufficient time gaps, structural changes in holding, pure cash-position harvesting, or intentional gain offsets. The advice work is to identify the loss positions, plan the strategy, document commercial rationale for any repurchase, and apply conservative time gaps. For retirees managing year-end tax outcomes, the wash sale conversation should be part of the standard tax-loss harvesting discussion — not an afterthought when the ATO sends a query letter.

Sources

• classic.austlii.edu.au — S177a
• classic.austlii.edu.au — S177d
• Australian Taxation Office (ATO) — Document
• Australian Taxation Office (ATO) — Capital gains tax
• classic.austlii.edu.au — S102.5