Mr. Obi is a Fellow of the Institute of Chartered Accountants of Nigeria. He is also an Associate Member of the Institute of Taxation of Nigeria. He retired on 31 March, 2010 as a Partner with Balogun Badejo & Co., Now BBC Professionals (Chartered Accountants) after putting in thirty-two productive years of service.

Before joining the firm of Balogun Badejo & Co. in 1978, Mr. Obi had worked with Colinson & Co., London and, before then, with the Nigerian Tobacco Company Limited.

He worked in various capacities with Balogun Badejo & Co and supervised several audit assignments including a few World Bank Assisted Projects and UNDP Supported Programs.