Australia doesn&#x27;t have a national identity card, and we don&#x27;t have anything that&#x27;s used like the SSN. Indeed, the Tax File Number (which identifies one&#x27;s tax record, similarly to how the IRS uses the SSN) is legally protected such that it&#x27;s a criminal offence for anyone other than the Tax Office, an employer, a financial institution or an accountant to even <i>ask</i> you to provide it. Centrelink Customer Reference Numbers (which are used for our equivalent of the Social Security program) aren&#x27;t legally protected (as far as I know), but since only half the population even has one, the only reason a private sector organisation will ask you for it is to check that you&#x27;re receiving social security benefits.<p>You do see driver&#x27;s licence and passport numbers being used, but it&#x27;s far from the de facto standard that the SSN is, and thus far less of a data security nightmare.