Professor Sanni was admitted into the Inner Bar as a Senior Advocate of Nigeria in 2021. He obtained his Bachelor's and Masters of Law Degrees from Obafemi Awolowo University (OAU), Ile-Ife in 1989 and 1992 respectively.

In 1991, he began his teaching career in Obafemi Awolowo University as a Junior Trainee Fellow; rose through the ranks to the position of Lecturer 1 and served as an Acting Head, Department of Business Law in 1997. earned a strong reputation in the legal service community.

In search of specialization and career advancement, he transferred his service to the University of Lagos (UNILAG) in 1999 and his career flourished therein. In 2003, he won the prestigious Fulbright Fellowship for foreign scholars, a 10-month Fellowship at the International Tax Programme of Beasley School of Law, Temple University, Philadelphia, USA. He was also appointed a Research Fellow of the Institute of International Law and Policy of the same University during the same period. In 2016, he had the singular honour of being simultaneously appointed as a Professor of Commercial Law and occupier of a Professorial Chair endowed by Lagos State in the University of Lagos for the Advancement of Taxation and Fiscal Matters. This earned him the sobriquet of “a Double Professor”, perhaps, the first in UNILAG especially in recent times.

Professor Sanni is a thoroughbred professional with a robust multi-disciplinary background. He is a Fellow of the Chartered Institute of Taxation of Nigeria (CITN). He has served the CITN in different capacities as a Dean, Faculty of the Indirect Tax and a member of the Taxation Standard Board. He is also a Fellow of the Nigerian Institute Chartered Arbitrators and a life member of the Nigerian Society of International Law. Since 2011, he has been involved in international arbitration under the International Chamber of Commerce (ICC) and the United Nations Commission on International Trade Law (UNCITRAL) Rules as well as domestic arbitration. He is the author of “Introduction to Nigerian Business Law”; the founder and publisher of the “Nigerian Revenue Law Reports” and African Tax Law Reports”, the first law reports devoted to tax cases in Nigeria and Africa respectively.

He has served the Federal Government of Nigeria in different capacities as a professional. He is a member of the Tax Advisory Committee (TAC) “Think-Tank” Group for the Federal Inland Revenue Service (FIRS). He served as the Chairman of the National Tax Policy Review Committee (NTPRC) in 2016. Contrary to the infamous tradition where reports of committees are subtly discarded, he was appointed the Chairman of National Tax Policy Implementation Committee (NTPIC) in 2017 to implement the key recommendations of the Revised National Tax Policy. He has been a member of the Federal Government Fiscal Reform Committee and Tax Advisory Committee which is responsible for incubating annual Finance Acts since 2019. He served as a member of the Advisory Group of the International Centre for Tax and Development (ICTD) from 2017 till date.

Professor Sanni is an advocate for sound corporate governance. He is the Chairman of the Board of Directors of Tax Technologies Limited, TaxAide Limited, Miles Drivers Recruitment, Budding Mothers Club (BMC), a Trustee of the United States Government Exchange Alumni Association of Nigeria (USGEAAN) (the umbrella body for beneficiaries of all exchange programmes sponsored by the United States Government in Nigeria), a Trustee of the Nigerian Law School Alumni Class of 1989-90.

He demonstrated exemplary vision and leadership during the early years in his career by coordinating a crop of six dynamic young lecturers to publish in 1998, the first book on Legal Methods in Nigeria, titled, “Introduction to Nigerian Legal Methods”. The book has remained the leading introductory legal text in Nigerian Universities and the West African sub region.

Professor Sanni maintains work life balance through sporting and social interactions. He is a member of Octagon 90, FS Club, House of Commons, Science Boys, Ife Recreation Club, Ikoyi Club 1938 and UNILAG Staff Club.