What is MHHS? How the biggest energy reform in decades will affect your business

You may be tempted to think MHHS is just another business energy acronym that won't affect your business.

You'd be wrong.

An ongoing nationwide transition to Market-wide Half-Hourly Settlement (MHHS) will affect more than 30 million domestic and business energy supplies across the UK. As of May 2026, the MHHS Programme confirmed they had reached 10 million initiations.

The UK energy regulator, Ofgem, has forecast MHHS will deliver £1.6 billion to £4.5 billion net benefits to British energy consumers.

The final rollout deadline is less than one year away, and the way you manage energy today could affect how ready you are and how much control you have when it happens.

We can help you understand what MHHS is, why it matters and how you can prepare for the switchover.

In this article:

• Learn what MHHS means for UK businesses.

• Understand how it directly impacts your business.

• Discover what you can do to prepare for the changes.

What is MHHS?

MHHS stands for Market-wide Half-Hourly Settlement. It’s a national programme that will soon require all electricity suppliers to settle energy use based on actual half-hourly data, rather than estimates.

There will be no more relying on estimations and sporadic manual readings. Your energy usage will be automatically recorded via readings every half an hour.

This means businesses like yours can see precisely when you're using electricity and gives the power grid operators a clearer picture of when people use power to accurately match demand with the right level of supply.

There could be greater scope to create tariffs that offer cheaper energy at off-peak times, potentially very useful in a world with an increasing demand for electric vehicle charging.

When does MHHS come in?

The MHHS rollout began in October 2025 and the final deadline is set for May 2027.

From June 2027 your business will need to comply with the new MHHS model.

The rollout is a huge technical challenge meaning it is being steadily phased in across suppliers rather than completed overnight.

Businesses should start planning for the change now to ensure a smooth, seamless transition.

How will MHHS affect your business? 

If your business has a smart meter or an advanced meter (AMR), you’ll likely be affected.

MHHS is designed with these meters in mind. They unlock the full benefits of half-hourly reporting for grid operators and small businesses.

For example, until now, business energy bills could be taken as a broad monthly reading. You may have used 1,000kWh in May. But that's all you know. The data is limited.

Under the new MHHS model, data will be reported in granular detail. You have used 1kWh between 3pm and 3:30pm. You have used 2kWh between 3:30pm and 4pm.

Those without smart or advanced meters will still fall under the MHHS model, but consumption estimates and profiling will be used in these instances.

This could lead to inaccuracies, fewer smart time-based tariffs available to your business and, ultimately, fewer opportunities to reduce your costs.

Eight steps your business should take right now

Use our helpful checklist to make sure you're MHHS-ready.

1. Check your meter is MHHS-ready

Not every electricity meter can record and send half-hourly usage data. MHHS depends on accurate data from your meter, so this is one of the first things to get clear.

• Smart or AMR meter installed? Your meter likely supports HH data. Billing and data services may have already changed or will be changed in the coming months. You do not need to do anything.
• Older or legacy meter installed? If you have a traditional meter, as opposed to a smart or AMR meter, you will not benefit from MHHS unless you upgrade before the deadline.

Why it matters for MHHS: Without a compliant meter, you won’t be able to move to half-hourly settlement. You could face delays or extra costs if you leave this too late.

2. Review your contract and pricing structure

Half-hourly settlement will change how your energy charges are calculated. You may be on a tariff with a single unit rate regardless of usage during the day or night.

It's helpful for you to know whether your:

• Pricing is based on estimated usage rather than half-hourly data.
• Tariff rewards flexible usage (day/night).
• Terms may need renegotiating once MHHS goes live.

Why it matters for MHHS: Contracts that don’t reflect half-hourly data may become outdated or less cost-effective. Getting ahead now could help you avoid mid-contract changes or missed opportunities.

3. Start accessing your half-hourly data

MHHS is based on actual half-hourly usage, not estimates. If your business has a smart or AMR meter, it’s likely already recording this data, even if you’re not billed on it yet.

Ask your supplier or energy supplier for access. It’ll show you:

• When your energy use peaks.
• Where you might be wasting energy.
• If there are gaps or irregularities in your data.

Why it matters for MHHS: Once MHHS goes live, this data will directly affect how you’re billed. Reviewing it now helps you avoid surprises and gives you time to adjust.

4. Plan for new flexible contract options

Half-hourly data unlocks the chance to reduce costs by shifting usage away from peak times.

Once MHHS is in place, suppliers can offer:

• Flexible or time-of-use tariffs.
• Savings for off-peak usage.
• Contracts that reflect real usage patterns.

Simple changes, like moving some processes to off-peak hours, could make a big difference.

Why it matters for MHHS: The system is designed to reward flexibility. The sooner you plan for this, the better you’ll be able to take advantage of it.

5. Make sure your data services are MHHS-ready

MHHS brings changes to how your data is handled. That includes new or updated roles for:

• Metering Operations Agents, Smart Data Service and Advanced Data Service
  
• Other third-party service providers

Some older setups may no longer meet the new requirements, and your supplier may need to update your arrangements.

Why it matters for MHHS: Even if your meter is ready, poor data handling can lead to errors, delays, or extra costs under the new system.

6. Speak to your finance team

More detailed data can mean more variable bills, especially if your usage peaks during high-demand periods.

Finance teams should prepare for:

• Greater variation in monthly charges.
• Budget forecasting based on actual usage patterns.
• Potential new tariff structures.

Why it matters for MHHS: Bills will better reflect real-time consumption. Forecasting and budgeting will need to adjust accordingly.

7. Ask the right questions now

Don’t wait for the deadline to find out where you stand. Start the conversation now with your supplier, your broker, or your account manager.

Questions to ask:

• Is our meter MHHS-compliant?
• When are we scheduled to transition?
• Can we see our half-hourly data now?
• Will our contract still work?
• What do we need to change?

Why it matters for MHHS: The earlier you understand what’s coming, the more control you’ll have over your setup, contracts and costs.

How we can help

Business energy is confusing. You know you need to stay on top of such a major cost, but that can be difficult while focusing on running your business and serving your customers.

We get it. We can support you.

Troo exists to help businesses like yours make sense of their energy needs, simplify complex information and make smart decisions that lead to real change and reduced costs.

We are not here to sell you a quick fix. We're here to understand what matters to you, offer clear advice, and take ownership of the hard parts, so energy becomes one less thing to worry about.

Book a free energy health check today for practical guidance on your business electricity, gas or water bills.