Getting your CGT cost base properly reviewed before you sell
Protect the asset and your financial position.
Best for: Owners preparing to sell who renovated along the way
Most investors know they should keep records for capital gains tax, but far fewer get their cost base actually reviewed and calculated before a sale is imminent. Costs that could legitimately reduce a capital gain are often missed simply because nobody has ever pulled them together into one figure.
What to check
- Whether you have a consolidated cost base figure at all, or just a folder of scattered receipts
- Whether all eligible costs are captured: purchase costs, stamp duty, legal fees, capital improvements, some holding costs where applicable
- What evidence exists for each item: contracts, settlement statements, invoices, bank records, photographs, plans, council approvals
- Whether any capital works have occurred that were never formally costed
- How long you have before a planned or likely sale
Who can help
Quantity surveyor
A formal cost base evidence report if records are incomplete.
Accountant
Your current cost base position and what's eligible.
TAKE ACTION · DOCUMENT REQUEST
One email, then an afternoon gathering documents
Request a cost base review
Copy this request and send it to your accountant or quantity surveyor.
USE AI TO HELP
Use AI to assemble the cost-base evidence pack before your accountant reviews it.
Best prompt for this issue
Help me assemble a cost base evidence pack for my accountant before selling. Using the records I list, organise costs into purchase costs, capital improvements and other categories, flag items with weak or missing evidence, and prepare the questions to ask my accountant. Do not determine which items are eligible.
Quick modes
WHAT TO PROVIDE
- all purchase records
- improvement invoices and payment evidence
- dates of any works
- existing cost base calculation if any
ASK AI TO GIVE YOU
- a short summary of the situation
- the main issue
- missing information
- risks to investigate
- questions to ask
- the next three actions
Privacy: do not paste passwords, tax file numbers, bank account details or other sensitive personal information into an AI tool. If a document contains personal details it doesn't need, redact them before uploading.
What happens next
The goal is to rebuild the evidence, not just the number. Your accountant determines the eligibility and treatment of each cost-base item; a quantity surveyor can provide construction-cost evidence where that's appropriate. On a property held many years with several rounds of improvements, this can materially change the calculated gain — and it's worth doing well before a sale is finalised, not during settlement.
Important considerations
- A quantity surveyor report doesn't universally replace missing invoices — it's one form of evidence among many, used where appropriate.
- Your accountant remains responsible for determining the tax treatment and eligibility of cost-base items.
- This is general information, not personal tax advice.
THE HOLD QUESTION
Do you know your actual cost base, or just your purchase price?
NOT SURE WHAT TO ASK AI?
Ask a Better Property Question
Most people don't need more AI — they need to ask AI better questions. Type your question (or skip it) and copy a prompt that makes any AI tool ask you the right things first.
I am trying to understand this property issue. Before answering, identify any important information that is missing. Ask me only the questions that materially affect the answer. Once I respond, explain the issue in plain English, separate facts from assumptions, identify the main risks and give me the next three actions. Flag anything that should be confirmed with a qualified professional.
Privacy: do not paste passwords, tax file numbers, bank account details or other sensitive personal information into an AI tool. If a document contains personal details it doesn't need, redact them before uploading. This is a way to prepare — not financial, tax or legal advice.
Not sure what else to review?
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