Gap-Filling in Nigerian Contract Law: An Empirical and Doctrinal Analysis of Implied Terms

The judicial implication of contractual terms to fill gaps in commercial agreements is one of the most consequential tools of contract law, yet the criteria and limits of term implication in Nigerian law remain analytically underdeveloped in both scholarship and judicial practice. This study provides an empirical and doctrinal analysis of implied terms in Nigerian contract law, examining 55 cases involving implied term arguments decided by Nigerian courts between 2018 and 2024 across commercial, employment, and real property contexts. Using a mixed-methods research design, the research quantitatively codes case outcomes by implication basis (business efficacy, obvious inference, statutory implication, or custom) and qualitatively analyses the judicial reasoning employed. Interviews with 25 commercial litigators in Lagos, Abuja, and Kano provide practitioner perspectives on how implied term arguments are framed and received in court. Findings reveal that Nigerian courts have not developed a consistent analytical framework distinguishing between terms implied in fact, in law, and by custom, leading to unpredictable outcomes in gap-filling disputes. The study also identifies a troubling judicial tendency to conflate contract construction and term implication. This research fills a significant gap in the empirical and doctrinal literature on Nigerian contract law. Recommendations include the adoption of a clear judicial framework for term implication modelled on the English Marks and Spencer v BNP approach, judicial training on contract construction, and academic engagement with gap-filling theory. Keywords: implied terms, gap-filling, contract law, business efficacy, Nigerian courts