The Market-wide Half-Hourly Settlement Explained (Without the Jargon)
The MHHS programme is one of the biggest changes in the UK energy market in decades. But what is it, why does it matter, and what should your business actually do about it? Let’s strip away the jargon.
If you’ve come across the term “Market-wide Half-Hourly Settlement” (MHHS), you’re not alone in feeling confused. Most explanations drown in technical detail. But the reality is simple: MHHS will change how every unit of electricity your business uses is measured, billed, and settled. And that means it will change your costs.
What is MHHS in plain English?
Today, many businesses are billed using estimates or occasional meter reads. Suppliers and the central market operator make assumptions about when you use electricity. These assumptions affect wholesale pricing, balancing charges, and your final bill.
MHHS replaces assumptions with real data. Every 30 minutes, your actual consumption will be recorded and settled against the wholesale market price for that period. This means bills reflect what you used, when you used it – no more broad averages.
Why is MHHS happening?
The UK energy market is under pressure to become more efficient, flexible, and transparent. As renewable generation grows, supply and demand fluctuate more rapidly. Old billing methods (based on profiles and averages) can’t keep up.
- Policy drivers: Support net zero and smarter energy use.
- Market efficiency: Reduce costs caused by imbalances.
- Fairness: Ensure customers pay for what they actually use.
MHHS is the mechanism to achieve this by settling everyone’s usage on the same half-hourly basis.
Who does it affect?
Every business in the UK. Whether you run a single office or manage multiple sites with multimillion-pound energy spend, MHHS applies. Smaller firms may notice little at first. But mid-market and large organisations will see a direct impact on procurement, budgeting, and reporting.
Facilities managers and office administrators will feel the operational shift. Finance teams will feel the budget implications. And leadership will want to know how it affects margins and reporting accuracy.
What changes for your business?
The short version: more accuracy, less assumption. But accuracy cuts both ways. If your usage patterns align with cheaper periods, MHHS could save you money. If not, costs could rise.
- Bills reflect time of use: Peak vs. off-peak matters more than ever.
- Estimated bills reduce: Better alignment between actual and billed usage.
- Settlement risk shifts: Suppliers pass on imbalances more directly.
- Data becomes central: Every 30-minute period adds to a larger consumption profile.
For businesses already investing in energy efficiency, MHHS rewards good behaviour. For those with inflexible demand, it exposes inefficiencies.
The benefits (if you’re prepared)
- Transparency: Bills reflect real usage, not opaque estimates.
- Control: Data visibility supports better procurement and reporting.
- Flexibility: Ability to shift demand into lower-cost periods for savings.
- Confidence: More accurate forecasting for finance teams.
These benefits only show up if you’re monitoring and managing data closely. Without oversight, MHHS can just as easily create budget shocks.
The risks (if you’re not prepared)
Every system change comes with risk. For MHHS, these include:
- Data gaps: Missing or inaccurate reads can create reconciliation shocks.
- Supplier errors: Billing system changes often produce mismatches.
- Budget volatility: Usage at peak times may suddenly cost more.
- Inaction: Assuming MHHS is “just an IT update” leaves businesses exposed.
MHHS Risks: Data Gaps, Supplier Errors, and Budget Surprises explores risk in detail.
What should businesses do now?
Preparation is the difference between MHHS being a cost or a saving. Steps include:
- Audit current data quality: are any sites on estimates?
- Centralise consumption data into one reporting view.
- Engage finance teams early: budget models must adapt.
- Consider demand-shifting opportunities (e.g., rescheduling heavy loads).
- Review contracts: ensure suppliers guarantee data accuracy.
MHHS and Cost Leakage
MHHS won’t automatically eliminate leakage. In fact, the transition period may increase errors and overspend. See our guide on How Energy Data Gaps Cost You More Than You Think for detail on why data quality is so critical.
Final thought: MHHS is a wake-up call
Energy is moving into a more transparent, data-driven era. Businesses that embrace this will gain control and savings. Those that don’t risk being left with higher costs and no clear answers for the board.
MHHS isn’t just a systems change. It’s a new way of managing energy. And the sooner you adapt, the more confident your business will be.
What’s next?
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