What MHHS Means for UK Businesses
The Market-wide Half-Hourly Settlement (MHHS) migration officially began on 22 September 2025, a month earlier than originally scheduled. Several major suppliers have already started updating billing systems and data processes in preparation for full market rollout.
The migration phase marks the point where the new settlement systems - developed by Elexon and approved by Ofgem - move from testing into live operation. The full transition of all electricity MPANs to half-hourly settlement will continue through mid-2027, supported by the Energy Networks Association (ENA) and other market participants.
Why Now & What’s Changing
On 28 May 2025, Ofgem published amendments to the MHHS Governance Framework following consultation feedback. Key parts of the Balancing & Settlement Code (BSC) have been updated, and Elexon has deployed new central systems to support migration.
The migration of all electricity MPANs toward the MHHS Target Operating Model is scheduled to begin from 22 October 2025, with completion expected by mid-2027.
How It Could Affect Businesses
MHHS is often discussed in terms of household impacts, but it has significant implications for business users too:
• Billing accuracy - costs will reflect actual usage, reducing estimation errors.
• Tariff flexibility - suppliers may offer time-of-use and load-shifting tariffs.
• Metering & infrastructure - some sites may require smart meter upgrades.
• Cash flow - shorter settlement periods mean less lag between usage and billing.
Businesses with flexible or smart contracts will benefit most from early preparation.
Understanding your bill
Some suppliers, including British Gas, have begun updating the top section of their electricity bills to reference the new Market-wide Half-Hourly Settlement (MHHS) process.
The note you’ll see explains that while your meter data will now feed into MHHS systems, your existing business contract or rates will not change as a result.
Fig1.British Gas communication showing where MHHS references appear on electricity bills. Source: British Gas
What Businesses Should Do Now
1. Conduct a meter audit - check if your meters are HH-capable.
2. Review tariff structures - understand how your supplier bills usage.
3. Prepare for dynamic pricing - plan for tariffs that reward off-peak usage.
4. Track updates from Ofgem and Elexon – this reform is still evolving.
Market-wide Half-Hourly Settlement (MHHS): Your Questions Answered
What is MHHS?
MHHS (Market-wide Half-Hourly Settlement) is an Ofgem-led reform managed by Elexon through the MHHS Programme. It changes how electricity consumption data is collected and billed, moving to half-hourly settlement for all customers.
Why is it being introduced?
The current process relies heavily on estimated usage data. MHHS will use smart meter data to enable more accurate billing, improve grid efficiency, and support decarbonisation goals.
When does it take effect?
The rollout is expected to begin in 2026, following system testing and consultation.
How will it affect my business?
Bills will reflect actual usage more closely. Businesses with flexible consumption patterns could benefit from time-of-use savings, while those with high peak demand may see increased costs.
Will I need to do anything?
Not immediately. Ensure your smart meters are working correctly and be prepared for potential tariff changes as suppliers adapt to half-hourly settlement.
Who’s overseeing it?
MHHS is governed by Ofgem, delivered by Elexon, and supported by the Energy Networks Association (ENA) and Distribution Network Operators (DNOs).
The Resolve View
MHHS is one of the most significant shifts in the UK electricity market for decades. While it brings complexity, it also creates opportunities for smarter energy use and better billing accuracy.
At Resolve, we’re closely tracking MHHS developments to help clients prepare.
If you’d like to understand how this change might affect your business, send us your latest bill for a free, no-obligation audit.
If you're looking to save money on your energy bills then why not get in touch today? The close relationships Resolve Energy has developed with over 24 of the UK’s biggest business energy suppliers allows our energy experts to source the best business energy rates available for your company right when you need them. Request a free quote today and start saving money on your energy.
