ETF tax records: AMMA statements and cost-base changes

Build the record when the transaction happens

A small recurring investment can create many acquisition parcels over several years. If each trade, reinvestment or corporate action is only visible inside an app, changing brokers can leave a difficult reconstruction job. Download the original records while they are easy to obtain.

The ATO’s share-record guidance identifies acquisition dates, amounts forming part of cost base, disposal dates and proceeds as important information. Relevant records can need to be kept well beyond the year you first buy an investment. Do not interpret a general tax-record rule as permission to delete evidence while the asset is still held.

Create a private folder structure by investment and financial year. Use a simple index naming the transaction date and document. You do not need an elaborate paid system to begin; you do need records that can be found and reconciled later.

Source: ATO: record keeping for share investments, official print section

Keep the purchase parcel separate from the current value

Suppose a fictional purchase is 100 units at $20 plus $10 brokerage. The cash paid is $2,010. In a simple illustration where that brokerage belongs in the cost base, the parcel starts at $20.10 per unit. A later market price of $24 does not rewrite that acquisition record.

If you buy another 50 units at $22 plus $5 brokerage, record a separate $1,105 parcel with its own date. Do not overwrite the first price with the new one. Averaging can be useful for a display, but the underlying transaction evidence still matters.

This example excludes foreign currency, special corporate actions and other adjustments. It demonstrates how to preserve information, not how to choose parcels for a tax outcome or apply a discount. Use current ATO rules for the actual calculation when a disposal occurs.

An AMMA statement does more than report cash

An Attribution Managed Investment Trust Member Annual statement can show tax components attributed to an investor and amounts affecting the unit’s cost base. The ATO’s AMIT guidance explains that this information belongs in the annual statement. Cash distributions and taxable amounts need not match one-for-one.

Read the issuer’s explanation alongside the statement rather than adding every line into a single income total. Some fields may be information for a tax-return label; others may be an adjustment to your ongoing records. Duplicating the same component can create errors.

Save the original statement and any corrected version. If a statement is replaced, mark which is current instead of keeping two indistinguishable copies. A short note explaining a correction helps prevent the old amount reappearing in a later spreadsheet.

Source: ATO: AMIT attribution and annual statement information

Track cost-base adjustments with their direction intact

Imagine a hypothetical statement instructs a $60 net increase to the cost base of a parcel whose recorded cost base is $2,010. The revised figure is $2,070. A separate hypothetical $40 decrease would produce $1,970 instead. These examples illustrate direction only; follow the actual statement’s labels and ATO instructions.

Do not assume every cash distribution reduces cost base or that every attributed taxable amount increases it. AMIT calculations have defined components, and statements can describe the net adjustment directly. If the wording is unclear, obtain an explanation from the issuer or tax agent before changing records.

Keep the financial year, original amount, adjustment and revised amount in separate columns. That preserves an audit trail. Overwriting one number without a note may make it impossible to explain why your figure differs from the original trade confirmation.

Source: ATO: personal investor CGT guide, managed-fund distributions

Reinvestment produces another acquisition record

A distribution reinvestment plan can create additional units even though no money leaves your bank account. Retain the date, amount applied, units acquired, price and any residual cash treatment shown on the issuer’s notice.

For a fictional $300 applied at $25 per unit with no rounding or costs, the record adds 12 units. It does not replace the original parcel or convert the payment into a new wage-funded contribution. Keep the distribution’s tax information and the new-unit record linked but distinct.

A broker’s transaction screen may not hold every issuer or registry document. Check where the fund supplies tax statements and reinvestment details. Record the correct ownership entity and account so a family member’s investment does not accidentally enter another person’s return.

Use prefill as a reconciliation step

Prefilled tax data can reduce manual entry, but it does not remove the need to check statements, ownership and completeness. Data may arrive at different times or be amended. A broker may know a sale occurred without having the complete cost history required for your calculation.

Compare the relevant statement with the tax-return information and investigate differences before lodging. Do not immediately add a missing-looking number if it is already included under another label. Keep a note of the explanation and the document relied upon.

If the investment changed brokers or involved a merger, split, return of capital or inherited holding, flag it for specific review. A normal purchase-and-sale shortcut may not describe the event correctly. The aim is to identify complexity early rather than solve it by guessing.

Keep law changes separate from record facts

A purchase date and cash amount remain historical facts even when tax rules change. Preserve them without assuming a future tax treatment. Current MoneySmart tax guidance notes announced 2026 Budget changes affecting investment taxation, so an old article’s discount or deduction shortcut should not be treated as permanent law.

This guide deliberately does not calculate a CGT discount, negative-gearing benefit or tax payable. Check the rules that actually apply to the transaction and financial year, including commencement and transitional provisions where relevant.

If a tax agent completes the return, provide the evidence and ask what further information is missing. A well-kept record lets the professional apply the applicable rules. A spreadsheet that already hard-codes an outdated concession can conceal the very issue you need reviewed.

Source: MoneySmart: investing and tax

Make the record easy to maintain

Use a monthly or quarterly routine to save new confirmations and reconcile unit totals. Then add annual statements when issued. Confirm that opening units plus acquisitions minus disposals matches the closing holding, allowing for documented changes.

Back up the records securely and keep sensitive identity information private. Avoid uploading statements containing TFNs, account credentials or unnecessary personal details into public tools. Elaris does not connect to a broker, import AMMA data or prepare a tax return.

Its budget tool can help allow for an actual tax payment once you have a verified amount, but it does not calculate that liability. The useful outcome here is a complete evidence pack: transaction records, annual statements, adjustment history and a short list of questions for the issuer or a registered tax agent.

A broker transfer deserves its own checkpoint. Save the old transaction history before access changes, then compare unit totals in the receiving account with the outgoing record. A transferred market value is not necessarily the historical acquisition information needed later. Keep the old confirmations and adjustment trail even if the new platform displays a neat opening figure. If the transfer involves a change of beneficial ownership rather than only administration, flag that distinction for tax advice instead of assuming the treatment is identical. Store a secure backup so changing platforms does not remove the only available copy.

FAQ: Can I delete purchase records after five years?

Do not assume five years from purchase is sufficient. The ATO’s CGT record guidance ties relevant retention to later events such as disposal, and additional circumstances can require records for longer. Keep the acquisition evidence while it remains relevant and verify the applicable retention rule before deleting anything.

FAQ: Is an AMMA statement the same as a bank payment?

No. It can contain attributed tax components and cost-base information that differ from cash received. Keep both the statement and payment records, then follow the appropriate labels. Ask the issuer or a tax agent about a mismatch rather than forcing them to equal one another.

FAQ: Does my broker calculate all capital gains correctly?

It may provide useful estimates, but it might lack earlier purchases, transferred holdings, reinvestments or annual cost-base adjustments. Reconcile its output against your full history. A brokerage profit display is not automatically the amount reportable under the applicable tax rules.

FAQ: What should I do with an unexplained adjustment?

Keep the original statement and write down the exact label, year and holding. Ask the issuer for the relevant explanation or take it to a registered tax agent. Avoid changing the sign or dividing the amount among parcels without a documented basis.

Sources and editorial notes

Sources checked 24 October 2026. Worked examples are fictional illustrations. Rules, eligibility and product terms can change; use the official source for your circumstances.

• ATO: record keeping for share investments, official print section ↗
• ATO: AMIT attribution and annual statement information ↗
• ATO: personal investor CGT guide, managed-fund distributions ↗
• MoneySmart: investing and tax ↗

General information, not an individual financial or legal assessment. AI-assisted drafting with source checks; independent professional review has not been completed. How we prepare our guides · Suggest a correction