We’ve officially passed the first major milestone on the MHHS timeline. As of 22 September 2025, the UK energy industry officially entered the next phase of the Market-Wide Half-Hourly Settlement (MHHS) programme. This reform is designed to make electricity billing more accurate, responsive, and aligned with actual usage—supporting the UK’s Net Zero goals and unlocking smarter energy choices for businesses.
What Changed?
If you’ve looked at your electricity bill or contract pack this week, you may have noticed that the MPAN Top Line (the top row of numbers on your electricity supply number) has changed.
Here’s what’s new:
- The Meter Time Switch Code (MTC) has been replaced by a Standard Settlement Configuration (SSC) ID.
- The SSC ID now has 4 characters instead of 3, meaning the meter line has grown from 8 to 9 characters.
- The Line Loss Factor Class (LLFC) has been renamed to DUoS Tariff ID, clarifying its role in distribution charges.
Importantly, this update is purely cosmetic – it’s simply a formatting change to align with MHHS and does not affect your electricity rates or prices.
Why MHHS Matters to Your Business
Market-Wide Half-Hourly Settlement (MHHS) isn’t just an industry update, it directly affects how you’re billed and the tariffs available to you. More accurate data means smarter tariffs, clearer insights, and the potential for lower costs.
If you want to see how these changes can be turned into a competitive advantage, check out our blog: Beyond Compliance: How to Turn MHHS into a Competitive Advantage.
What’s Next on the MHHS Timeline?
The next milestone arrives in late October 2025, when the migration window opens. At this stage, advanced and smart meters will begin migrating onto the MHHS framework, starting the transition to full half-hourly settlement.
For businesses, this means it is vital to check that all eligible sites are ready and that your meters are fully compliant. Ensuring this now will avoid delays, prevent potential billing issues, and allow you to take advantage of the new tariff structures as soon as they become available.
Preparing Your Business
The benefits of MHHS won’t arrive automatically, and without preparation businesses risk billing errors, delays, or being locked into unsuitable contracts. To stay ahead, your systems need to be aligned with the new MPAN format and settlement rules.
At Black Sheep Utilities, our role is to make the transition straightforward by reviewing your meters, checking compliance, updating contracts, and transforming half-hourly data into clear insights that support efficiency and cost savings.
Act Now
Market-Wide Half-Hourly Settlement (MHHS) is here, it’s mandatory, and acting early is the best way to reduce risk while unlocking smarter tariffs and long-term savings.
We’re offering a MHHS readiness check to assess your meters, MPAN, and contracts – get in touch today to make sure your business is ready to take advantage of the opportunities ahead.