What does it take to manage a 48-fold increase in data volume while continuing to reliably serve millions of energy customers across the UK?
By May 2027, all UK energy suppliers need to migrate their entire electricity portfolio into the UK’s new Market-wide Half-Hourly Settlement (MHHS) programme. The mandate requires that suppliers shift from estimates and daily smart meter reads to processing half hourly data for every smart meter. That’s a 48-fold increase in settlement data volume, translating to 500 billion half-hourly readings per year processed across the industry.
For OVO, one of the UK’s largest energy retailers, Kaluza is the trusted partner with the expertise, experience and modern platform to deliver this data migration without disrupting retail operations, customer service or regulatory compliance. Just last week, the MHHS programme announced that 50 percent of meter points have now migrated to the new half-hourly arrangement. We’re taking this opportunity to share more about Kaluza’s partnership with OVO on this important change.
The solution
To meet this industry-defining mandate, Kaluza built the integrations required to exchange settlement messages under the new MHHS arrangements, working alongside OVO's appointed data services and Data Integration Platform (DIP) connectivity. Then Kaluza seamlessly ingested and processed the exponential increase in settlement data, which is used to financially reconcile supplier wholesale energy purchases with actual customer consumption.
Kaluza prioritised the experience of retail operations staff and how this new regulation would affect them. By handling the technical complexity of the new MHHS data flows in the backend, Kaluza minimised the impact on staff, and kept daily interactions within Kaluza Customer Care largely unchanged.
To guarantee readiness, the platform was rigorously load tested end-to-end for the new flow volumes, proving the capability to easily process over 625,000 consumption data flows per hour. Kaluza also completed the complex MHHS qualification process in collaboration with OVO, ensuring the platform was ready to operate in the new settlement programme at the same time as the retailer’s operations team.
The results
Kaluza successfully achieved full MHHS qualification and readiness in April 2026, enabling OVO to complete a robust and stable migration programme of one of the UK’s largest and most complex retail energy portfolios.
Delivering at pace
Two months after going live, migrations are running at the maximum permitted daily volume, and OVO is on track to migrate the majority of its portfolio by the end of the year.
Ahead of schedule
The MHHS migration is happening on a rolling basis through May 2027. But Kaluza and OVO began migrating live meter points two months ahead of their original schedule, moving alongside the market's first movers while many suppliers were still completing qualification testing.
At scale
Kaluza migrated a retailer with approximately 12% market share in the UK, demonstrating our ability to handle a large industry-wide regulatory shift at scale. We have been ready to operate in the new settlement market since September 2025, so we were handling incoming customers from the moment the industry went live. When OVO achieved full qualification in May 2026, the platform shifted into full migration mode without missing a beat: simultaneously moving OVO’s existing customer portfolio and every new acquisition onto the new settlement framework in a single, uninterrupted programme.
Frictionless rollout
Even while Kaluza was doing the migration, agents could handle new MHHS read disputes and billing events exactly as they did before. Retail staff avoided disruptive retraining and maintained full operational efficiency, resulting in a major regulatory shift executed with no impact on customer service.
Ready for future clients
By successfully completing the rigorous MHHS qualification process alongside the OVO group, Kaluza has already done the heavy regulatory lifting. Any future UK retail client operating on Kaluza can inherit this MHHS readiness, bypassing major qualification hurdles, and significantly decreasing their time to market. Furthermore, with markets globally moving towards settlement periods as low as 5 minutes, Kaluza has proven its ability to work with clients to process data and deliver on large industry-wide projects in any market.
Built for what comes next
Beyond compliance, Kaluza’s upgraded event-driven architecture provides the foundation for future retail innovation. The Kaluza platform empowers retailers to launch dynamic time-of-use tariffs, scale smarter flexibility propositions and deliver highly accurate customer billing.
Want to see the platform in action? Get in touch here.
