CGT Property Valuation Guide

Written by: Sydney Property Valuers Editorial Team
Last updated: 14 July 2026

This guide explains when a capital gains tax (CGT) property valuation is required in Australia, what a defensible CGT valuation report should contain, and how to prepare so the valuation holds up if the Australian Taxation Office (ATO) reviews it. It is written for property owners, investors and executors — and for the accountants and tax advisers who guide them.

A CGT valuation is not the same as a market appraisal from a real estate agent. Where a tax position depends on the market value of a property at a particular date, the ATO generally expects an objective, well-evidenced valuation prepared by a suitably qualified valuer. An appraisal, an online estimate or a rates notice figure is rarely sufficient on its own.

This is general information only and is not tax advice. Your accountant or registered tax agent should confirm whether a valuation is required for your circumstances, and the exact date the valuation should be prepared “as at”.

Who this guide is for

This guide is useful for:

Property investors selling or restructuring an investment property.
Homeowners who have started renting out a former main residence, or moved back into a former rental.
Executors and beneficiaries dealing with an inherited property.
Accountants and tax advisers who need supportable market-value evidence for a client’s return.
Solicitors advising on transfers between related parties.

When a CGT property valuation is needed

CGT valuations most commonly arise in the following situations. Your adviser can confirm which applies to you.

First use of a main residence to produce income

When a property that was your main residence first starts producing income (for example, you move out and rent it), a market value as at that date is often needed to reset the cost base. Because this date can only be valued after the fact, a retrospective valuation is usually required.

Change from investment to main residence

Where a property changes from income-producing to a main residence, or its use changes part-way through ownership, a valuation at the relevant date helps apportion any taxable gain.

Inherited and deceased estate property

For property passing through a deceased estate, a market value at the date of death may be needed — particularly for assets acquired by the deceased before 20 September 1985, or where the main residence exemption interacts with a later sale. This overlaps with probate valuation work.

Transfers between related parties

Transfers that are not at arm’s length — for example, between family members or related entities — generally use the market value substitution rule, so independent evidence of market value is important even where no money changes hands.

Small business CGT concessions

Determining eligibility for the small business CGT concessions can require the market value of relevant assets to be established at a particular test time.

What a defensible CGT valuation report should contain

To be relied on for tax purposes, a CGT valuation should be more than a figure. A supportable report generally includes:

The effective date of value (which may be a past date).
The basis of value — usually market value — and the purpose of the valuation.
A clear description of the property and its legal interest.
The comparable evidence relied on, appropriate to the valuation date.
The valuation approach and reasoning.
Any assumptions, limitations or special instructions.
The valuer’s qualifications and signature.

Objective, supportable evidence is the point. A retrospective valuation for a date years ago must be built on comparable sales from around that period, not on today’s market.

Documents to prepare

Gathering these before instructing a valuer reduces delays and improves accuracy:

Property address and title details — including the certificate of title or a recent title search.
Ownership and purchase details — contract of purchase, settlement date and purchase price.
The relevant CGT date — confirmed by your accountant (e.g. date first rented, date of death, date of transfer).
Prior valuations or reports, if any exist for the property.
Rates and land tax notices.
Lease agreements, if the property is or was tenanted.
Renovation and capital improvement records — dates, scope and cost.
Building plans or strata records, where relevant.
Any legal or accountant instructions setting out the purpose and required date.

Retrospective valuations explained

A large share of CGT valuations are retrospective — valuing the property as at a date in the past. These are more involved than a current valuation because the valuer must reconstruct the market as it was, using sales evidence from around the relevant date rather than recent sales.

Clear instructions on the exact date, and any evidence about the property’s condition at that time (photos, renovation records, tenancy history), make a material difference to the quality of the report.

Common mistakes to avoid

Using an agent’s appraisal instead of a valuation. An appraisal is a selling tool, not independent market-value evidence.
Getting the valuation date wrong. The date must match the tax event. A valuation as at the wrong date can be unusable.
Leaving the valuation too late. Retrospective evidence is harder to source the longer you wait, and photos or records of the property’s past condition may be lost.
Ignoring capital improvements. Renovations completed before the valuation date change the value and should be documented.
Assuming one valuation covers every purpose. A valuation prepared for a mortgage or insurance is not automatically appropriate for CGT.
Not confirming the purpose with your accountant first. The purpose and date should be settled before the valuer is instructed.

Professional use note

Accountants, tax advisers and solicitors are welcome to share this guide with clients as a general preparation resource before independent valuation advice is obtained. It is designed to help clients understand why the valuation date matters, what evidence supports a market-value figure, and which documents to gather — reducing back-and-forth once a valuer is instructed.

This guide is general information and does not replace advice tailored to the client’s matter.

Related services and resources

Capital gains tax valuations — our service page for CGT and tax-purpose reports.
Retrospective valuations — for past-date valuations.
Investment property valuations — for portfolio and sale-related valuations.
Deceased estate / probate valuations — where CGT interacts with an estate.

Need a CGT valuation for your matter?

If you or your client needs independent market-value evidence for a capital gains tax matter, our team can confirm the appropriate valuation date, the documents required and the right report format. Request a quote and we’ll set out what’s needed for your circumstances.

The information on this page is general in nature and is not legal, financial or tax advice. Capital gains tax outcomes depend on individual circumstances — please obtain advice specific to your matter from a registered tax agent or accountant.