Andrew formed Carson & McLellan PPB in 1992, with Ian Carson, after working with Coopers & Lybrand from 1981 to 1992.  He has been a registered Liquidator since 1992 and an Official Liquidator of the Supreme Court of Victoria since 1996.

In June 2000, Andrew created a precedent whereby, as Receiver and Manager, the Supreme Court of Victoria appointed him as Voluntary Administrator to the same company. This enabled a sizeable manufacturing firm to continue trading.  He also set one of the few examples whereby as Liquidator of a company, he was subsequently also appointed as Voluntary Administrator, enabling a sizeable distribution to be made to the company's creditors.

Andrew specialises in the Voluntary Administration process, working with the secured lender, the directors, their accountant and their solicitor, to explore every opportunity for saving a company and its business.

Since 2005, Andrew McLellan has been appointed by the Federal Court to assist in reviewing and regularising a number of Management Investment Schemes (MIS), requiring him to work with both the MIS operators, ASIC and Primelife Corporate Limited.