GN 01744.315 Australian Customer Reference Number (CRN)
The Customer Reference Number is a 10-digit number, 9 numeric and 1 alpha at the end. The first number indicates the state in which the claimant lives (1-7). Not everyone in Australia has a CRN. Numbers are generally assigned when a person begins receiving payments. Children could have a number if they received a Family Allowance. The number has no linkage to other offices in Australia, such as the tax file, super annuation, and health insurance.