The market value substitution rule, explained.

The market value substitution rule is the CGT mechanism that replaces the figures the parties actually used with the asset's market value. Under s 116-30 of the ITAA 1997, market value is substituted for your capital proceeds where you receive nothing for a CGT event, or where the parties were not dealing at arm's length and the proceeds differ from market value. Section 112-20 does the mirror-image job on the acquisition side, substituting market value into the cost base in comparable circumstances. In practice, the rule turns gifts, family transfers and restructures into market-value transactions — which makes the valuation evidence, not the paperwork price, the number that matters. Oliver Group prepares signed, independent valuations for exactly these transactions.

What does the market value substitution rule actually do?

The rule has two limbs, and they mirror each other. On the disposal side, s 116-30 of the ITAA 1997 substitutes market value for your capital proceeds in two situations: where you receive no proceeds at all for a CGT event, or where you and the other party were not dealing with each other at arm's length and your actual proceeds are more or less than the asset's market value. On the acquisition side, s 112-20 does the same job in reverse, substituting market value into the cost base in comparable circumstances — so the person receiving the asset does not inherit an artificial price either. The rule exists because CGT cannot run on prices people choose for their own reasons: where the price is missing or manufactured, the law taxes the transaction as though it had happened at market value. That single substitution changes the character of the exercise. Once either limb is engaged, the number that matters is no longer the number in the contract or the minute book — it is the number a valuation can defend. Every consequence that flows from the event — the gain, the losses, any concessions claimed against it — is then calculated from that substituted figure.

When does the rule bite?

The rule is not an anti-avoidance provision reserved for egregious schemes. It is triggered by ordinary transactions that happen every week inside family groups, private companies and trusts — usually without anyone pricing them the way a stranger would. The recurring patterns:

• ·Gifts and nil-consideration transfers. Handing shares to a child, transferring an asset into a family member's name, moving property for love and affection — where no proceeds are received, s 116-30 deems the proceeds to be market value, and the giver is taxed as if they had sold at that value.
• ·Family and related-party dealings. Sales between spouses, siblings, parents and children, or between entities the same people control, where the price was set by the relationship — or by a tax objective — rather than by bargaining.
• ·Restructures. Moving assets between companies, trusts and individuals within a group. Each movement is a CGT event in its own right, and the group's internal transfer price carries no weight if the dealing was not at arm's length.
• ·Trust dealings. In specie distributions, transfers between trusts, and dealings between trustees and beneficiaries — situations where a genuinely bargained price rarely exists at all.
• ·Mates-rates sales. A deliberately soft price to a friend, a long-serving employee or an incoming business partner. The discount is real commercially, but it does not reduce the CGT position: where the dealing was not at arm's length, market value is substituted for the actual proceeds.

Does 'arm's length' just mean 'not related'?

No — and this is the most misapplied part of the rule. The legislation asks whether the parties were dealing with each other at arm's length in the particular transaction, not whether they are related. It is a test of conduct: did each party apply independent judgment and bargain for its own interest? Related parties can deal at arm's length — a genuine negotiation between siblings, each separately advised, each pushing for their own outcome against real market evidence, can qualify. And unrelated parties can fail the test — strangers who coordinate a price to serve a collateral purpose, or who simply do not bargain at all, are not dealing at arm's length merely because they are unrelated. The practical consequence cuts both ways. A related-party sale supported by real bargaining and contemporaneous market evidence can stand on its actual price; an unrelated sale conducted without genuine bargaining can still attract substitution. What the ATO examines is the dealing itself — how the price was formed, what each side knew, who pushed back — and the dealing is proved by evidence, not by pointing at the family tree.

What does 'market value' mean once it is substituted?

When market value is substituted, it takes its ordinary meaning from case law — principally the willing buyer and willing seller test in Spencer v Commonwealth: the price a willing buyer would pay a willing seller, dealing with the asset as it really stood at the relevant date. Three features of that test matter in substitution cases. First, the buyer and seller are hypothetical, but the asset and its circumstances are real — the business or interest is valued as it actually stood, with its actual earnings, contracts, risks and dependencies at the date of the CGT event. Second, the valuation date is the date of the transaction, not the date someone gets around to asking. Events that happened afterwards, and could not reasonably have been foreseen at the date, cannot be fed back into the number. Third, market value is a question of evidence, not assertion: a figure is only as strong as the methodology and the contemporaneous material behind it. That is why substitution disputes are, in substance, valuation-evidence disputes — the legal question of whether the rule applies is usually settled quickly, and the fight is over whose number should stand.

What have the tribunal and the courts actually decided?

Two recent decisions bracket the rule from opposite ends. In Moloney [2024] AATA 1483, a related-party restructure triggered the substitution rule, and the dispute became a straight contest of valuation evidence: the Commissioner's expert put the value at roughly $10.6 million, the taxpayer's expert at roughly $3 million. The tribunal preferred the taxpayer's expert, and the concessions the taxpayer had claimed survived. In Kilgour [2025] FCAFC 183, the transaction ran the other way: a $31 million sale to News Corp was an arm's-length dealing, so substitution did not apply — and no minority discount was available against the actual, coordinated sale price. The High Court refused special leave, so that outcome stands. Read together, the cases make the architecture plain: whether substitution applies turns on the dealing, and once it applies, the better-evidenced valuation decides the number.

What does defensible evidence look like — and when should you commission it?

The strongest position is a signed, independent valuation prepared as at the transaction date — ideally commissioned before the transaction completes, so the value can inform the deal rather than be reverse-engineered after it. A defensible file is one another valuer could pick up and test: it states the methodology and why it was chosen, rests on evidence that existed at the valuation date, discloses the information relied on, and is prepared with the ATO's market valuation guidance in mind. A retrospective valuation as at a historical date is possible — and often necessary once a review has started — but it is always the harder exercise, because it must reconstruct the world as it stood and resist the pull of hindsight.

• ·Commission before, not after. A valuation obtained before the transfer is contemporaneous evidence; one obtained after a review letter arrives reads like advocacy, whatever its quality.
• ·Value at the transaction date. The relevant market value is the value at the date of the CGT event — not today's value, and not last financial year's accounts rolled forward.
• ·Independence matters. A figure produced by someone with a stake in the outcome carries little weight. A valuer on a fixed fee, with no success interest in the number, carries more.
• ·Document the working. Conclusion-only letters fail. The file should show the method, the inputs, the evidence and the reasoning, so the number can be replicated and tested.

What does an independent valuation cost — and where does Oliver Group's role stop?

Oliver Group's fees are fixed and quoted before work begins. An Indicative Snapshot from $990 + GST (around 5 business days) gives an indicative value range only — it is not a signed report, and the fee is fully creditable toward an Essential engagement. Signed valuations start with Essential from $1,495 + GST (10–14 business days). Comprehensive from $3,995 + GST (15–25 business days) suits related-party transfers and restructures that warrant more depth. The Defensible Valuation File from $8,995 + GST (25–35 business days) is built for positions likely to be tested, and the Valuation Range & Scenario Review from $12,995 + GST (30–45 business days) covers multiple scenarios or dates. Retrospective valuations add $495 per historical date, each additional entity adds $750, and rush delivery adds 30%. Clients referred by an accountant or lawyer receive 10% off. One boundary matters and we hold it strictly: Oliver Group is an independent valuer, not a registered tax agent, and we give no tax, legal or financial advice. We provide the market value evidence. Whether and how the substitution rules apply to your transaction — and the tax position ultimately taken — stays with your accountant or adviser.