About us
The second indigenous accountancy firm in Nigeria.
Founded on 17th September, 1956 by the late Dr Z. O. Ososanya, HLB Z. O. Ososanya & Co. (formerly Messrs Z. O. Ososanya & Co.) is one of Nigeria's pioneering indigenous accountancy firms. Over the decades, we have grown into a leading name in professional accounting, providing exceptional financial services to clients nationwide. In August 1998, we restructured and rebranded under our current corporate identity.
As a member of HLB International, a prestigious global network of professional accounting firms and business advisers, we leverage international expertise to seamlessly handle cross-border engagements. With over 2,195 partners and 25,000 professionals in more than 700 offices across 150+ countries, our network ensures that our clients benefit from world-class financial solutions and specialised industry insights.
1956Founded as Messrs Z. O. Ososanya & Co.
1998Restructured; renamed HLB Z. O. Ososanya & Co.
2ndIndigenous accountancy firm in Nigeria
150+Countries in the HLB International network
Succession
The firm's leaders across seventy years.
Z. O. Ososanya & Co.1956 – 1998
- 1956 – 1978 Dr Z. O. OsosanyaFounder & first Senior Partner
- 1978 – c. 1996 Chief S. O. OguntimehinSenior Partner
- c. 1996 – 1998 T. A. Oyelami & A. OlatawuraJoint Senior Partners
HLB Z. O. Ososanya & Co.1998 – date
- 1998 – 2004 A. Olatawura & M. B. ShosanyaJoint Senior Partners
- 2004 – 2023 Olufemi A. OsosanyaManaging Partner
- 2023 – date Babatunde J. KolawoleManaging Partner
The 1996 handover is recorded as the firm best recalls it, and is being confirmed for the seventieth-anniversary records.
Our philosophy
Vision, mission & values.
Our vision
To be the natural choice as vision enablers to all clients.
Our mission
To sustain a practice that is committed to building a leading firm of highly motivated, innovative and responsive employees who are dedicated to maintaining best practice in providing total quality services to all clients.
Our core values
- Helping both current and potential clients develop their true potentials by offering a range of professional services with economic insights, interesting ideas and geographic reach.
- Maintaining long-term relationships based on trust with our clients.
- Building a legacy of competence, integrity and adding value to clients' business.
- Nurturing a future generation of competent professionals by providing intensive training for our staff.
- Acknowledging God's benevolence in all that we do.
Experience
Trusted across Nigerian business.
Client names are held in professional confidence — these are the sectors the firm serves.
- Banking & Financial Institutions
- Conglomerates & Listed Entities
- Oil, Gas & Energy
- Construction & Real Estate
- Manufacturing
- Hospitality
- Non-Governmental Organisations
- Other industries
Landmark engagements
- Public sector & privatisation
- Reporting accountants
- Valuation, investigation & recovery
- Due diligence, investigation & governance
Network
Our affiliated companies.
Sanyasec Limited
Corporate secretarial services, regulatory compliance and statutory matters — supporting businesses in maintaining governance and legal integrity.
Techtrain Consulting Limited
Business strategy and management consulting — helping organisations navigate operational challenges and optimise performance.