Accounting separation provides separate accounts for wholesale and retail operations. The accounting separation regime has evolved into its current form over a number of years. Its legislative basis is section 151BU of the Trade Practices Act 1974 which enables the ACCC to make record keeping rules that require Telstra (and other telecommunications carriers) to provide the ACCC with information to carry out its regulatory responsibilities. Grahame O'Leary ouitlines the arrangements in this research note.