What the ATO Already Knows About You

The ATO does not rely only on the figures in a tax return. It receives information from government bodies, financial institutions, employers, businesses and other third parties, then uses that information to check what taxpayers report. If you receive a data-matching enquiry, the practical task is to identify and reconcile the records behind the difference.

What data matching means

Data matching compares information from different sources. The ATO uses it to pre-fill some labels, detect discrepancies, identify people who may need to lodge and support compliance activity. Its published protocols describe particular programs, the data obtained and how it will be used.

A discrepancy is not automatically proof that your return is wrong. Third-party records can be incomplete, duplicated, allocated to the wrong period or reported against the wrong taxpayer. The difference needs to be investigated rather than simply accepted or dismissed.

Where third-party information can come from

Depending on the program and tax issue, information may be reported by:

• employers and superannuation funds;
• banks and other financial institutions;
• companies, managed funds and investment registries;
• property-related bodies and service providers;
• digital platforms and sharing-economy operators;
• crypto asset service providers;
• other Australian government agencies; and
• overseas jurisdictions through information-exchange arrangements.

The relevant source should be identified from the ATO correspondence or clarified with the officer. Avoid guessing which dataset produced the question.

Pre-fill is not the same as post-lodgment matching

Pre-fill makes information available while a return is being prepared. It is useful, but the taxpayer still needs to check that the information is complete and belongs in the correct return and year.

Post-lodgment matching compares lodged information with data held by the ATO. The third-party data may arrive or be processed at a different time. That is one reason an enquiry can arise after a return has been assessed.

Reconcile before you explain

Start with the figure or transaction in the letter. Obtain the source statement, then trace it to the relevant return label and working papers. A useful reconciliation shows:

1. the amount reported by the third party;
2. the amount included in the return;
3. any difference in timing, ownership or classification; and
4. the documents supporting that explanation.

If the return is wrong, calculate the full effect before responding. If the third-party data is wrong, identify the exact error and consider whether the reporting organisation also needs to correct its record.

Crypto data: transactions are not the same as taxable gain

ATO crypto data may help identify acquisitions, disposals and accounts. Transaction values alone do not necessarily establish the taxable gain or loss. Cost base, fees, transfers between wallets, personal-use questions and the nature of the taxpayer's activities may all require analysis.

Export records from every relevant exchange and wallet, preserve transaction identifiers and reconcile transfers so they are not mistaken for disposals. Do not answer from a single exchange dashboard if assets moved across platforms.

Rental information: ownership and expenses still matter

Property-related data can identify ownership, transfers and rental activity, but it may not resolve how income and expenses should be apportioned or whether expenditure is immediately deductible, depreciable or capital. Co-ownership and changes in use can also create differences between a gross data figure and the return.

Reconcile agent statements, bank records, ownership documents and invoices. A clear schedule is more useful than sending an unlabelled folder of receipts.

Prepare a response that can be checked

Use the ATO's question numbers, give a concise answer and point to the matching attachment. If an estimate or assumption is necessary, label it and explain the basis. Avoid absolute claims that the source records do not support.

Also check whether the explanation has consequences elsewhere. A difference may affect another income year, a related entity, GST, capital gains or deductions. Understanding that wider position before replying reduces the risk of a second avoidable correction.

When the enquiry may need closer review

Professional help may be appropriate where the datasets are large, several entities or years are involved, the ATO's figure is gross rather than net, records are missing, or the response could affect penalties. The aim is a defensible reconciliation: where the third-party information is correct, say so; where it is not, show why.