The market value substitution rule: when the ATO ignores your sale price

The market value substitution rule is a capital gains tax rule that replaces the actual price in a transaction with the asset's market value. It applies when you deal other than at arm's length, or receive no or non-market consideration, so your CGT is worked out on what the asset is really worth rather than what changed hands. It works on both sides of a deal: the capital proceeds when you dispose of an asset, and the cost base when you acquire one. This guide explains when the rule applies, the arm's length exception, what market value means, and why a valuation matters. It is general information, so confirm your position with a qualified adviser.

Key takeaways

• The market value substitution rule replaces the actual price with the asset's market value for tax purposes.
• It applies to gifts, and to non-arm's length dealings where the price is not the market value.
• If you genuinely deal at arm's length, your actual price stands, even if it is below market value.
• The rule affects both your capital proceeds on disposal and your cost base on acquisition.
• Establishing market value usually needs an independent valuation report from a qualified valuer.

What is the market value substitution rule?

When you sell an asset at arm's length, CGT is worked out on the price you actually receive. The market value substitution rule steps in when that price is missing or unreliable.

In those cases, the rule substitutes the market value of the CGT asset for the actual amount. The capital gain is then calculated as if the asset had changed hands at its true market value.

When does the market value substitution rule apply?

The rule is triggered in a few specific situations at the time of the CGT event.

No consideration, such as a gift

If you receive nothing for an asset, for example when you gift it, you are taken to have received its market value at the time of the CGT event. A gift does not escape CGT.

Non-arm's length dealings

If you and the other party were not dealing at arm's length, and what you received was more or less than the market value, your capital proceeds are replaced with that market value.

Where the proceeds cannot be valued

If the capital proceeds cannot be valued, for example a non-cash benefit that is hard to price, market value is used instead.

The arm's length exception

This is the crucial limit on the rule. If you genuinely deal at arm's length, your actual price stands, even if it is below market value.

Arm's length means the parties act independently, with neither controlling the other. A genuine arm's length transaction in the open market is respected, so a low but real price is not overridden. The rule targets dealings that are not at arm's length, not every bargain.

Both sides of a transaction: capital proceeds and cost base

The rule cuts both ways, which surprises many people. On disposal, it can lift your capital proceeds to market value, increasing your gain. On acquisition, it can set the first element of your cost base to market value, affecting the gain when you later sell.

So when property passes between related parties for little or nothing, both the person disposing of it and the person acquiring it may be treated as transacting at market value.

What does market value mean?

Market value has its ordinary meaning: the price a willing buyer and a willing seller would agree in the open market, neither being under pressure and both acting knowledgeably.

It is not a forced sale price, and it excludes any special value that a particular buyer might pay above what the general market would. Market value reflects what other buyers would realistically pay.

The ATO guidance and case law both apply this ordinary meaning, testing what a hypothetical purchaser would pay against real market prices.

How is market value determined for tax purposes?

For a figure the ATO will accept, you should determine market value with a proper market valuation, ideally an independent valuation report from a qualified or professional valuer.

The valuer applies recognised methods, most often the market approach using comparable sales, and sometimes the income approach or cost approach, consistent with accepted industry standards. The report records the valuation date and the evidence behind the figure.

A defensible valuation turns market value into a figure that holds up if the ATO reviews it, and for a significant amount a private ruling can add certainty.

Common situations where the rule applies

The market value substitution rule shows up more often than people expect, usually in family and related-party dealings.

• Gifting property to a child or other family member.
• Transfers to related parties for less than market value.
• Moving assets into a trust or SMSF where the dealing is not at arm's length.
• Below-market transfers as part of a larger transaction or restructure.

In each case, CGT is based on the asset's market value, not the nominal amount, so a valuation is needed.

Why the rule matters

The rule exists to stop people understating a price to reduce CGT, for example by selling an asset cheaply to family. The same market value concept underpins other tax provisions too, such as GST margin scheme valuations.

The practical point is simple: if a transaction is not at arm's length, you need a defensible market value to report the correct capital gain, or you risk an ATO adjustment, interest and penalties.

How Valato helps

Valato provides independent property valuations for tax purposes across Australia, current or retrospective, prepared to establish market value where the substitution rule applies.

Each report documents the market value with comparable sales evidence, ready to support your CGT position on a gift, a family transfer, or a move into a trust or SMSF. Compare the valuation options or order a valuation, and confirm the tax treatment with your accountant.

The bottom line

The market value substitution rule replaces the actual price with an asset's market value when you do not deal at arm's length, or receive no market consideration, so CGT reflects real value rather than a nominal figure. It works on both the capital proceeds and the cost base, and the key exception is a genuine arm's length deal. Where it applies, an independent valuation gives you the defensible figure you need, so get one and confirm the treatment with your adviser.

Frequently asked questions

General information only: This article is general in nature and does not take into account your individual circumstances. It should not be relied on as tax, financial or legal advice. Capital gains tax rules are complex; confirm the current rules and your own position with a qualified professional before making decisions about your property or tax position.