The Central Bank of Kenya (CBK) has ushered in a landmark reform in the domestic financial system with the launch of the Kenya Shilling Overnight Interbank Average (KESONIA). Effective September 1, 2025, KESONIA introduces a standardized benchmark for overnight interbank lending rates, significantly improving transparency, efficiency, and stability within Kenya’s money markets. This marks a critical step in aligning Kenya’s financial framework with international best practices.
For decades, overnight lending among commercial banks has been a key measure of liquidity in Kenya’s interbank market. However, the absence of a formalized benchmark created inconsistencies, making it challenging for market participants and policymakers to gauge short-term borrowing costs with clarity. KESONIA bridges this gap by offering a transparent and reliable reference rate, streamlining market operations and enhancing the ability of stakeholders to make informed decisions.
Early performance indicators suggest smooth adoption of the new benchmark. By September 11, 2025, KESONIA stood at 9.45 percent, slightly below the 9.48 percent recorded the previous week. Interbank activity also demonstrated resilience, with average daily transactions rising to 21 from 20, while the traded value remained steady at KSh 11.4 billion. These figures underscore that the new rate has integrated seamlessly into market operations without disrupting liquidity conditions.
Beyond technical adjustments, CBK positions KESONIA as a vital monetary policy tool. The benchmark strengthens the monetary policy transmission mechanism by providing clearer pricing signals for banks and supporting predictability in interest rate movements across the broader economy. This impacts a wide spectrum of financial instruments, from government securities to private sector credit, ultimately enhancing economic stability and growth prospects.
Investor confidence also stands to benefit significantly from this reform. Benchmark rates are widely recognized as indicators of financial market health. With a credible and transparent interbank reference rate in place, Kenya strengthens its financial market reputation, boosting domestic and international investor trust. This enhances Kenya’s ability to attract foreign capital flows and deepens participation in domestic financial markets.
The success of KESONIA will hinge on its acceptance and consistent performance over time. If effectively managed, it could serve as the cornerstone of Kenya’s short-term money market, much like LIBOR and SOFR in global markets. By introducing KESONIA, CBK is laying a strong foundation for a modernized financial system that supports sustainable economic growth, fosters resilience, and places Kenya firmly on the path to financial innovation.
