Across Africa, payment infrastructure is moving fast. Kenya sits at the centre of that shift, with PesaLink processing over KES 1.1 trillion in transactions in 2024 alone and the Central Bank actively upgrading systems to the ISO 20022 standard. Yet many financial institutions remain anchored to legacy infrastructure, not out of ignorance, but out of genuine fear.
Payment rails modernisation carries real operational risk, and when migrations go wrong, users pay the price through failed transactions, delayed settlements, and broken trust. This blog outlines how institutions can modernise with precision, protecting both infrastructure stability and the customer relationships built over the years.
Understanding the Current State of Payment Rails
What Are Payment Rails?
Payment rails are the networks, protocols, and settlement systems that move money between accounts and institutions. In Kenya, this ecosystem includes the Central Bank’s RTGS infrastructure, the PesaLink interbank transfer network, and mobile money rails that connect bank accounts to platforms such as M-Pesa. Each rail operates under distinct technical standards, regulatory requirements, and settlement timelines.
Why Do Institutions Delay Modernisation?
Many financial institutions manage intricate, critical payment ecosystems where core functions like card processing and wire transfers operate on hybrid infrastructure. Because essential processes like fraud detection and reporting depend on this stability, altering any element risks systemic failure. Consequently, many banks prefer delaying modernization to avoid immediate disruptions, despite the increasing long-term costs of remaining on legacy systems.
The Real Risk: User Disruption During Migration
What Disruption Looks Like for End Users
User disruption during migration rarely announces itself as a major outage. It surfaces as a salary credit that arrives four hours late, a supplier payment that bounces without explanation, or a mobile banking session that times out mid-transfer. For retail customers and SMEs operating on tight cash cycles, these are not inconveniences. They are financial incidents that erode confidence and trigger churn.
The Business Cost of Getting It Wrong
Gartner estimates that average IT downtime costs exceed $5,600 per hour, rising significantly in real-time transaction environments. In Kenya’s context, migration failures allow rivals to capture market share from dissatisfied users. Furthermore, data migration errors can lead to corrupted records, unauthorised transactions, regulatory fines, and permanent reputational harm.
Adopt a Phased Migration Approach
The single biggest mistake institutions make during payment infrastructure migration is attempting a full system cutover at once. The most successful migrations happen in phases, covering one rail, one use case, or one product surface at a time, with parallel operation until confidence is established.
A structured phased approach for Kenyan institutions should focus on:
- Starting with high-impact, lower-complexity rails, such as interbank transfers, before moving to more complex settlement and card-processing layers
- Running legacy and modern systems in parallel during each phase, validating output accuracy before decommissioning the old environment
- Setting clear go/no-go criteria for each phase, including transaction success rates, reconciliation accuracy, and latency benchmarks
- Defining rollback procedures in advance, allowing teams to safely reverse a deployment without escalating the incident
Modernisation fails when viewed solely as a technical task. Phased migration ensures institutions manage the transition with the strategic rigour of a product launch.
Build on API-First and Middleware Layers
For institutions not ready to replace their core systems, middleware and API layers offer a lower-risk path forward. Middleware enables banks to bridge the gap between legacy core systems and modern digital platforms. Rather than replacing the core—a costly and high-risk undertaking—it allows banks to add new capabilities on top of existing infrastructure.
An API-first design provides standardised interfaces, allowing for the integration of new services without modifying core systems. Adopting this approach enables banks to reduce maintenance costs by almost 35% and speed up product launches by 30%.
Why This Matters in the Kenyan Market
Kenya’s banking infrastructure modernisation makes API readiness a competitive baseline rather than a differentiator. PesaLink has introduced a developer sandbox allowing fintechs to test integrations safely and bring services to market faster, marking a strategic shift towards an open, industry-led innovation platform connecting banks, fintechs, and digital platforms through Kenya’s interbank rails.
Institutions that are not API-ready risk being excluded from the next generation of integrated financial services in the region.
Prioritise Real-Time Testing and Rollback Planning
Communication as a Strategy Tool
Continuous synthetic testing must replace limited pre-launch UAT. Monitoring for benchmark variances across migration phases is essential, specifically tracking:
- Transaction latency relative to agreed service levels
- Exception and error rates during parallel operation windows
- Reconciliation gaps between legacy and modern ledger entries
- Customer-facing failure signals, such as declined transactions or timeout errors
Each migration requires a defined rollback plan. Attempting a simultaneous transition for all rails, counterparties, and workflows introduces significant, avoidable risk.
User communication during migration is vital. Scheduled notices, status updates, and support channels minimise complaints and prove the institution is managing the transition responsibly. Informed customers handle temporary friction much better than those facing unexplained failures.
What Every Payments Team Should Keep in Mind
Digital payments transformation is a continuous institutional capability, not a finite project. Successful teams treat each migration like a product launch, utilising success criteria, monitoring, and contingency planning.
Three principles consistently distinguish successful migrations from costly ones:
- Treat monitoring infrastructure as a core investment, not an afterthought
- Align operations, compliance, and product teams around shared milestones, not just technical deliverables
- Measure outcomes in customer experience terms, alongside system performance metrics
How WFIS Kenya Supports Payment Modernisation
The World Financial Innovation Series (WFIS) in Kenya, scheduled to take place on 2 March 2027 at the Edge Convention Centre, Nairobi, supports financial institutions in managing the operational and strategic complexities of real-time payment system transitions.
The event’s curated agenda focuses on frameworks that preserve service continuity while enabling institutions to align with Kenya’s ISO 20022 standards, open banking developments, and evolving CBK regulatory requirements.
For institutions ready to move from planning to execution, WFIS Kenya provides the advisory and integration support to do that without putting users or operations at risk.
Frequently Asked Questions
What are payment rails?
Payment rails are the underlying networks and protocols that route money between banks, accounts, and financial systems during every transaction.
Why do legacy payment systems create problems for modern banks?
Legacy systems escalate maintenance costs, restrict API integration, hinder development, and complicate regulatory compliance.
How long does a typical payment rails migration take for a Kenyan bank?
Timelines vary by institution size and complexity, but phased core payment migrations typically run between 12 and 36 months.
What is an API-first approach?
It involves building core functions as standardised interfaces to allow easy integration without infrastructure rebuilds.
How should banks communicate changes to their customers’ systems?
Use early warnings, app alerts, and helpful support teams to keep users updated and supported throughout the entire migration process.