ato logo

How we undertake data matching

Last updated 8 June 2021

Identity matching

The ATO's identity-matching capability is used to identify individual and or non-individual entities reported to us from a number of external sources. The process is mainframe-based and uses an ATO-designed software solution (technical standard). Aligning with guideline 4.7, this standard supports all of our data-matching programs.

We use over 60 sophisticated identity-matching techniques to ensure we identify the correct taxpayer when we obtain data from third parties. This technique uses multiple identifiers to obtain an identity match. The identity-matching process appends matching information to the original reported transaction to include an ATO identifier number and a three-character outcome code that indicates to the user the level of matching confidence for the transaction. For example, where a name, address and date of birth are available, all items are used in the identity-matching process. Very high confidence matches will occur where all fields are matched.

Additional manual processes may be undertaken where high confidence identity matches do not occur, or a decision taken to destroy the data with no further action. Our manual identity-matching process involves an ATO officer reviewing and comparing third-party data identity elements against ATO information on a one-on-one basis, seeking sufficient common indicators to allow confirmation (or not) of an individual's identity. We commonly call this process manual uplifting.

Data analysts use various models and techniques to detect potential discrepancies, such as under-reported income or over-reported deductions. Higher risk discrepancy matches will be loaded to our case management system and allocated to compliance staff for actioning.

Lower risk discrepancy matches will be further analysed and a decision made to take some form of compliance or educational activity, or to destroy the data.

To maintain integrity of the administration of the tax and superannuation systems, only those with a direct and genuine ‘need to know’ can access the technical standards for our identity and discrepancy matching solutions.

Where administrative action is proposed, additional checks will take place to ensure the correct taxpayer has been identified. The taxpayers will be provided with the opportunity to verify the accuracy of the information before any administrative action is taken.

See also:

What we do before we amend a return

The data will be used to make it easier for individual taxpayers, by providing tailored messages in our online services. This will assist taxpayers to check they have provided the correct data and are correctly meeting their reporting obligations.

After a return is lodged, where we detect a discrepancy that requires verification we will contact the taxpayer usually by phone, letter or email.

Before any administrative action is taken, taxpayers will be given the opportunity to verify the accuracy of the information obtained by us. Taxpayers will be given at least 28 days to respond before administrative action is taken.

For example, where discrepancy matching identifies that a taxpayer may not be reporting all of their income, but in fact they're reporting the income under another entity, the taxpayer will be given the opportunity to clarify the situation.

The data may also be used to ensure that taxpayers are complying with their other tax and superannuation obligations, including registration requirements, lodgment obligations and payment responsibilities.

In cases where taxpayers fail to comply with these obligations, after being reminded of them, prosecution action may be instigated in appropriate circumstances.

Where a taxpayer has correctly met their obligations, the use of the data will reduce the likelihood of contact from us.

Making a privacy complaint

Our privacy policy outlines how we collect, hold and disclose data and explains what you can do if you're not satisfied with the way your information has been treated.

If you're not satisfied with how we have collected, held, used or disclosed your personal information, you can make a formal complaint by:

ATO Complaints

PO Box 1271


If you're not satisfied with the outcome of the privacy complaint, you can contact the Office of the Australian Information Commissioner. More details on the process can be found on the OAIC website at Link.