Previously, we wrote a blog explaining what Market-wide Half-Hourly Settlement (MHHS) is and why it matters for your business. Now, it’s time to move from the “what” to the “when.” This article breaks down the official MHHS implementation timeline into clear, actionable stages so your business can plan ahead and meet the key deadlines.
Market-wide Half-Hourly Settlement (MHHS) is no longer a distant concept – it’s a major reform reshaping how UK businesses’ energy usage is measured and billed. In December 2024, Ofgem approved a six-and-a-half-month delay to key MHHS milestones to allow thorough testing. As a result:
-
Migration starts in late October 2025
-
Migration completes in May 2027
-
The new (faster) settlement timetable goes live in July 2027
The countdown is on. Below we break down the critical dates – and what your business needs to do at each step.
What This Means for Your Business
1. The Metering Imperative: Every site must have a SMETS2 smart meter or an advanced AMR meter. Without one, your site cannot be migrated to MHHS, making this the most critical action for businesses.
2. Track Your Milestones:
- Oct 2025: Migration starts – ensure your sites are eligible.
- Oct 2026: Supplier Qualification deadline – ensure your supplier is MHHS-compliant.
- May 2027: Final migration deadline – all sites must be fully migrated.
3. Changes to Industry Roles: Familiar terms like “Meter Operator” (MOP) and “Data Collector” (DC) are being replaced with “Metering Service” and “Data Service”. These new terms will appear in contracts and communications moving forward.
4. A Live, Evolving Programme: The MHHS Programme Plan is regularly updated, most recently in August 2025. Staying informed of the latest updates is essential to avoid disruption and ensure smooth compliance.
Immediate Actions for Businesses
The first step is to audit your metering setup and upgrade any non-smart or non-AMR meters immediately, as these are essential for MHHS compliance.
But here’s the catch: chasing individual suppliers for MHHS qualification updates or migration schedules can be time-consuming and unclear. That’s where we come in.
At Black Sheep Utilities, we take that burden off your desk. Our team works directly with suppliers on your behalf, confirming their MHHS readiness and mapping out your transition plan — so you don’t have to.
We’ll keep you informed with the latest MHHS and Elexon updates, plus our own practical guidance, ensuring you never miss critical milestones. Most importantly, we provide expert oversight — simplifying compliance, minimising risk, and saving valuable time.
MHHS is a fundamental shift in the UK energy landscape. Businesses that prepare early – by checking meters, ensuring supplier compliance, and staying ahead of the timetable – will avoid last-minute disruptions and maintain smooth operations.
Black Sheep Utilities is already helping businesses do exactly that. We’ll make sure your sites are ready, your supplier is compliant, and your energy settlement stays seamless.
The time to act is now — and we’re here to guide you every step of the way.