SARB: Jibar to Zaronia Transition Governance in South Africa

• South Africa will permanently discontinue Jibar on 31 December 2026, following a No new Jibar milestone May 2026.
• Rashad Cassim confirmed mid-2025 Jibar exposures reached R43 trillion domestically and over R107 trillion offshore.
• Zaronia adoption has grown from R6.4 billion to more than R200 billion as markets adjust to the new reference rate.
• The transition shifts debt calculations from forward-looking rates to backward-looking compounded overnight index rates.
• Legal and treasury teams must modernize debt documentation and governance frameworks to replace spreadsheet-based controls.

For corporate legal advisors and financial regulatory lawyers, managing Jibar to Zaronia transition governance South Africa requires an immediate review of legacy corporate debt documentation and underlying treasury control frameworks.

South Africa is approaching a decisive restructuring of its financial benchmark infrastructure as market participants prepare to replace the Johannesburg Interbank Average Rate (Jibar) with the South African Rand Overnight Index Average (Zaronia). Under the national benchmark reform roadmap, regulators have set a strict "No new Jibar" milestone of 1 May 2026 to prevent the creation of additional Jibar-referenced contracts. The transition will culminate in the permanent discontinuation of Jibar immediately following its final publication on 31 December 2026.

The financial magnitude of this transition is vast. Speaking at the MPG Conference 2025, Rashad Cassim revealed that domestic Jibar-linked exposure stood at approximately R43 trillion as of mid-2025, while offshore exposure was estimated to exceed R107 trillion. Meanwhile, market adoption of Zaronia is rapidly expanding, with total volume climbing from R6.4 billion to over R200 billion. For corporate legal advisors and financial regulatory lawyers, managing Jibar to Zaronia transition governance South Africa requires an immediate review of legacy corporate debt documentation and underlying treasury control frameworks.

The migration represents more than a routine legal or financial update; it marks a fundamental shift in reference rate mechanics. While Jibar functioned as a forward-looking interest rate determined and fixed at the beginning of an interest period, Zaronia operates as a backward-looking overnight index rate. Published directly by the South African Reserve Bank, Zaronia reflects historical overnight money market transactions rather than prospective quotes.

This structural divergence means interest liabilities can no longer be determined upfront. Instead, treasury teams must calculate compounded overnight rates over the course of the interest period. In-house counsel must ensure corporate issuers update debt documentation with clear, auditable fallback clauses and precise interest determination formulas to maintain SARB Zaronia benchmark reform compliance while mitigating potential contract disputes upon Jibar's final cessation.

Beyond legal papering, the move to compounded overnight calculation methods exposes severe operational vulnerabilities within corporate debt administration controls South Africa. Historically, many corporate treasury functions managed debt servicing, coupon resets, and payment notices using manual spreadsheets, decentralized email chains, and localized institutional knowledge. While those unstructured processes sufficed for static, forward-looking rates, they introduce significant operational risk in a compounded overnight rate environment.

Under heightened scrutiny from auditors, institutional investors, and regulatory bodies, issuers must be able to demonstrate an unbroken chain of control for every payment instruction and rate reset. Legal teams and corporate governance officers should urge issuers to dismantle legacy spreadsheet workflows and implement standardized operational governance. Addressing these systemic vulnerabilities ahead of the Jibar discontinuation deadline 2026 is critical to preserving market confidence and ensuring bulletproof treasury administration across capital markets.

In-house counsel and financial regulatory lawyers must review corporate debt documentation and treasury control frameworks ahead of the 1 May 2026 'No new Jibar' milestone and final cessation on 31 December 2026. Legal teams should advise corporate issuers to establish auditable fallback clauses and standardized operational governance to eliminate manual spreadsheet risks when calculating backward-looking compounded Zaronia rates.

Source: Original reporting via South African financial market disclosures