The UK electricity market is undergoing one of its biggest changes in years, with the introduction of Market-Wide Half-Hourly Settlement (MHHS).
If you’ve recently received an email or letter from your electricity supplier mentioning MHHS, you might be wondering what it actually means for your business, whether your electricity bills will change, or if there’s anything you need to do.
The good news is that, for most businesses, much of the transition will happen behind the scenes.
However, MHHS could eventually change how suppliers price electricity, how businesses monitor their consumption and the types of electricity contracts available.
In this guide, we explain what MHHS is, when it’s happening, how it could affect your business electricity bills and whether you need to take any action.
MHHS at a glance: What businesses need to know
If you’re looking for a quick explanation of Market-Wide Half-Hourly Settlement, here are the key points:
- What is MHHS? A major reform of the Great Britain electricity market, introducing half-hourly settlement for electricity supplies.
- When is it happening? Migration began in October 2025 and is scheduled to finish on 7 May 2027, with the final settlement timetable change planned for July 2027.
- Will my electricity bills increase? Not automatically. MHHS itself doesn’t introduce a universal price increase, although some supplier-specific metering or data charges could change.
- Will I need a new electricity meter? Not necessarily. Existing compatible smart and advanced meters can support half-hourly data collection, while other meters can be settled using estimated consumption data.
- Do I need to renew my electricity contract? No. MHHS is an industry settlement reform, not a contract renewal deadline.
- Do I need to do anything? For most businesses, no immediate action is required. Your supplier should contact you if anything is needed.
What is Market-Wide Half-Hourly Settlement (MHHS)?
Market-Wide Half-Hourly Settlement (MHHS) is an industry-wide reform that changes how electricity consumption is measured and accounted for across Great Britain.
The programme was initiated by energy regulator Ofgem and is being delivered through an industry-wide programme involving Elexon, electricity suppliers and other market participants.
Historically, many smaller businesses have had their electricity usage allocated to different times of day using estimated consumption patterns, even when their meters record their actual total consumption.
MHHS changes this by moving electricity supplies onto a settlement system that operates in 30-minute intervals.
For businesses with compatible smart or advanced electricity meters, suppliers can use actual half-hourly consumption data to understand more accurately when electricity is being used.
This gives suppliers a clearer picture of electricity demand and helps them match the electricity they purchase more closely with their customers’ consumption.
Importantly, half-hourly settlement doesn’t mean you’ll automatically be charged a different electricity price every 30 minutes. Your electricity contract still determines how you’re charged.
How does half-hourly settlement work?
A typical day is divided into 48 half-hour periods.
Under the traditional settlement system, many businesses without half-hourly metering have had their electricity usage allocated across these periods using standard consumption profiles.
These profiles estimate how electricity is used throughout the day based on the type of supply and its overall consumption.
MHHS allows the industry to move away from relying so heavily on these estimates.
For example, consider two businesses:
- Business A: A bakery that uses most of its electricity early in the morning, running ovens and other equipment before opening.
- Business B: A restaurant that uses most of its electricity during the evening, particularly when its kitchen is busiest.
Both businesses might consume the same total amount of electricity annually, but their usage patterns are very different.
With actual half-hourly consumption data, suppliers can better understand these differences rather than relying on broadly estimated patterns.
Over time, this could lead to more personalised electricity pricing and opportunities for businesses that can move some of their consumption to less expensive periods.
Is half-hourly settlement the same as half-hourly billing?
No, and this is an important distinction.
Half-hourly settlement relates to how electricity consumption is accounted for between suppliers and the wider electricity market.
Half-hourly billing or time-of-use pricing relates to how a customer is charged for electricity consumed during different periods.
For example, a business could have its electricity settled every 30 minutes while continuing to pay a single fixed unit rate for every kilowatt-hour consumed.
Equally, a business with an existing day/night electricity tariff would continue to be charged according to its agreed contract terms.
MHHS changes the settlement arrangements behind the scenes. It doesn’t automatically change your electricity tariff.
Why is MHHS being introduced?
MHHS is designed to create a smarter, more efficient electricity market that better reflects how electricity is actually consumed.
There are several potential benefits.
1. More accurate electricity settlement
Using actual half-hourly meter data where available reduces the industry’s reliance on estimated consumption profiles.
This allows suppliers to forecast demand more accurately and better understand the cost of supplying electricity to different customers.
2. Better visibility of business electricity consumption
Businesses with compatible smart or advanced meters may benefit from more detailed information about their electricity usage.
This could help identify periods of unusually high consumption, unnecessary overnight usage or opportunities to reduce energy waste.
3. More flexible electricity contracts
As suppliers gain a better understanding of when electricity is used, MHHS could encourage the development of more flexible pricing options.
For example, businesses that can operate certain equipment outside expensive peak periods might benefit from future time-of-use electricity contracts.
However, these contracts won’t necessarily suit everyone, particularly businesses that have little flexibility over their operating hours.
4. Supporting renewable energy
Electricity generation from renewable sources, such as wind and solar, varies throughout the day.
More accurate consumption data could help the electricity system respond better to these changes, encouraging businesses to use electricity when renewable generation is more readily available.
This supports the wider transition towards a lower-carbon electricity network.
When is MHHS happening? The 2026–2027 rollout explained
The transition to Market-Wide Half-Hourly Settlement is already underway.
The industry began migrating electricity supplies to the new arrangements in October 2025, with the process taking place in stages.
The key milestones are:
|
Date
|
MHHS milestone
|
|
October 2025
|
Industry-wide migration of electricity supplies begins.
|
|
28 October 2026
|
Milestone 14 successfully completed, confirming that all suppliers have the required systems and services to accept supplies under the new MHHS arrangements.
|
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7 May 2027
|
Scheduled completion of the industry-wide migration programme.
|
|
2 July 2027
|
Planned transition to the new, shorter electricity settlement timetable.
|
The successful completion of Milestone 14 in October 2026 marked a significant step forward for the programme.
However, it doesn’t mean every business electricity supply has already migrated.
Individual businesses will move to the new arrangements at different times, depending on their electricity supplier and meter type.
Your supplier should communicate any important changes or actions required.
You can follow the latest dates on the official MHHS Programme website.
Will MHHS affect my business electricity bill?
This is understandably one of the biggest questions for business owners.
MHHS does not automatically mean your electricity prices will increase or decrease.
For most businesses with an existing fixed-rate electricity contract, the introduction of MHHS is not itself a reason for their agreed contractual unit rates to change.
However, there are a few things worth understanding.
Changes to electricity bills
Some suppliers may change how information appears on bills, including meter details, consumption information or settlement-related terminology.
Depending on your supplier and meter type, you may also notice changes to billing arrangements or how certain metering and data service charges are displayed.
Changes to future electricity pricing
Over time, suppliers may use more accurate consumption data when calculating electricity prices.
This could be particularly relevant for businesses with substantial electricity demand or unusual consumption patterns.
For example, suppliers may increasingly consider when a business consumes electricity, rather than relying solely on its overall annual consumption.
Network and other non-commodity charges
Some business electricity contracts allow suppliers to pass through changes in network, government or other regulated charges.
There may also be changes to metering and data service costs as suppliers move to the new arrangements.
Whether any charges can change during your existing contract will depend on its terms and your supplier’s approach.
The important point is that MHHS should not be confused with an automatic increase in electricity prices or a requirement to sign a new contract.
If your supplier advises that charges will change because of MHHS, it’s worth asking for a clear explanation of what is changing and why.
Will businesses need a smart meter for MHHS?
Not necessarily.
Although smart and advanced meters play an important role in MHHS, businesses without them are still included in the new settlement arrangements.
The difference is how their half-hourly consumption information is obtained.
Businesses with smart or advanced meters
Compatible meters can record electricity consumption in half-hourly intervals and provide that information remotely.
This gives suppliers a more accurate understanding of actual electricity usage throughout the day.
It may also give your business access to more detailed consumption information, helping you identify opportunities to improve energy efficiency.
Businesses with traditional electricity meters
Traditional meters that cannot record actual half-hourly consumption can still be included in MHHS.
In these cases, half-hourly settlement information may be estimated using consumption profiles and available meter readings.
Your supplier may recommend or arrange a smart meter upgrade where appropriate, particularly if your existing meter cannot support future requirements.
However, MHHS migration does not automatically mean every business must have a new physical meter installed.
What if my business already has a half-hourly electricity meter?
Larger businesses have used half-hourly electricity metering for many years.
If your business already has a half-hourly meter, MHHS is unlikely to introduce the same fundamental changes to how your electricity consumption is recorded.
However, there may still be changes to the industry services and processes supporting your meter.
For example, existing Meter Operator (MOP), Data Collector (DC) and Data Aggregator (DA) arrangements are being reorganised under new metering and data service roles.
If your business independently appoints these service providers, it’s worth checking how your arrangements will be managed under MHHS and whether any changes to contracts or charges are proposed.
What WeSave recommends for existing half-hourly supplies
For businesses with larger commercial electricity supplies, we recommend looking beyond the unit rate when reviewing a contract.
Depending on your metering arrangements, your overall electricity costs may also include:
- Metering and data service charges.
- Agreed supply capacity (kVA).
- Distribution Use of System (DUoS) charges.
- Transmission Network Use of System (TNUoS) charges.
- Excess capacity or reactive power charges.
- Other non-commodity costs, depending on your contract.
These charges aren’t all being introduced by MHHS, but they can already make a significant difference to the overall cost of a half-hourly electricity contract.
For example, a business may secure a competitive unit rate but still be paying more than necessary because its agreed kVA capacity is substantially higher than its actual requirements.
That’s why reviewing the complete electricity supply arrangement is important, rather than focusing solely on the pence-per-kWh price.
You can learn more in our guide to Half-Hourly Meters, kVA and Network Charges.
Will MHHS change my MPAN or electricity meter profile class?
You may notice some changes to the information shown on your electricity bill.
Your Meter Point Administration Number (MPAN) is the unique reference used to identify your electricity supply.
As part of MHHS, some of the information associated with MPANs is being updated to reflect the new settlement arrangements.
For example, many electricity supplies previously identified by traditional profile classes will move towards new settlement classifications.
Some businesses with smart or advanced meters may notice their profile class change to 00, a designation historically associated with half-hourly metered supplies.
Other technical information within the top line of the MPAN may also change, including the codes used to describe meter configurations and network charging arrangements.
However, this doesn’t necessarily mean your business has been fitted with a traditional commercial half-hourly meter or that you automatically need a separate Meter Operator contract.
The important distinction is between the settlement arrangements applied to your supply and the actual type of meter installed.
For ordinary metered business electricity supplies, the underlying supply reference remains in place, even where associated classification information changes.
Will MHHS make business electricity cheaper?
Potentially, but there are no guaranteed savings simply from being migrated to MHHS.
The main long-term opportunity comes from giving suppliers and businesses better information about electricity consumption.
For example, a business with significant electricity usage overnight might eventually have access to different pricing options compared with one that primarily operates during peak daytime hours.
Similarly, businesses with electric vehicle charging, refrigeration, manufacturing equipment or battery storage may have opportunities to manage when they use electricity.
However, not every business can change its operating hours or move consumption to cheaper periods.
For many businesses, comparing the overall annual cost of electricity contracts will remain one of the most important ways to identify competitive pricing.
That means considering unit rates, standing charges, applicable network costs and contract terms rather than simply choosing a tariff because it offers cheaper electricity at certain times.
Could MHHS affect my next electricity renewal?
Potentially.
As more detailed half-hourly consumption data becomes available, suppliers may increasingly use businesses’ actual usage patterns when calculating renewal prices.
This could create opportunities for some businesses, particularly those with substantial consumption outside peak periods.
However, it could also mean that businesses with different consumption patterns receive different prices, even where their total annual electricity usage is similar.
At WeSave, we compare the estimated total annual cost of electricity contracts, taking account of consumption, unit rates, standing charges and other applicable costs.
This helps ensure you’re comparing contracts on a like-for-like basis rather than looking at headline unit rates alone.
If your contract is approaching its end date, you can also read our Business Energy Renewal Guide for 2027.
Do businesses need to do anything about MHHS?
For most businesses, there’s no need to take immediate action.
The migration process is being coordinated by electricity suppliers and the wider industry.
Nevertheless, there are a few sensible things you can do:
- Check communications from your supplier. If any changes to your meter, billing arrangements or data services are needed, your supplier should explain them.
- Keep your meter readings up to date. If your business still submits manual readings, continue doing so unless your supplier advises otherwise.
- Understand your electricity consumption. If you have access to half-hourly data, it can be useful for identifying when your business consumes the most electricity.
- Review any proposed changes to charges. If your supplier contacts you about new metering, data or billing charges, ask for a breakdown and check how they relate to your existing contract.
- Review your electricity contract when appropriate. MHHS is not a reason to rush into a new agreement, but comparing electricity prices as part of your usual renewal planning remains worthwhile.
If you’re approaching the end of your electricity contract, WeSave can help you compare business electricity prices from a wide panel of suppliers.
Common MHHS misconceptions businesses should be aware of
With such a significant industry change, it’s understandable that businesses may receive mixed messages about what MHHS means.
Here are three important misconceptions worth clearing up.
“MHHS means I need to renew my electricity contract immediately.”
False. MHHS is an industry settlement reform, not a contract renewal deadline.
You don’t need to sign a new electricity contract simply because your meter is being migrated to the new settlement arrangements.
“My electricity prices will automatically increase because of MHHS.”
Not necessarily. MHHS doesn’t introduce a universal price increase.
While individual suppliers may make changes to certain metering or data service charges, any impact will depend on your specific arrangements and contract terms.
“Every business must have a traditional half-hourly electricity meter.”
False. All electricity supplies are moving to half-hourly settlement, but that doesn’t mean every business must have a traditional commercial half-hourly meter installed.
Smart meters, advanced meters and traditional meters can all be accommodated within the new arrangements, although the method of obtaining consumption data will differ.
Frequently asked questions about MHHS
Is Market-Wide Half-Hourly Settlement mandatory?
Yes. MHHS is an industry-wide regulatory
reform, with electricity suppliers required to migrate
electricity supplies into the new arrangements.
Individual customers do not generally need to
arrange this themselves.
When will MHHS be completed?
The current programme timetable schedules the
completion of electricity supply migration for
7 May 2027, with the final settlement
timetable transition planned for
2 July 2027.
These are industry milestones rather than dates
on which every business will experience a
visible change.
Does MHHS mean I need to renew my electricity contract?
No. MHHS is not an electricity contract
renewal deadline. You don’t need to sign a new
electricity contract simply because your supplier
is migrating your meter to the new settlement
arrangements.
Can I switch electricity suppliers during MHHS?
Yes. Businesses can still switch
suppliers in accordance with their existing
contractual arrangements. MHHS migration doesn’t
prevent normal supplier switching, although
the relevant industry processes need to be
managed correctly.
Will I be charged different electricity rates every 30 minutes?
Not automatically. MHHS changes how
electricity is settled within the industry.
It doesn’t automatically move businesses onto
variable or half-hourly electricity pricing.
Your contract determines the rates you pay.
Will MHHS affect business gas?
No. Market-Wide Half-Hourly
Settlement applies to electricity supplies
in Great Britain, not business gas contracts.
Does every business need a half-hourly meter?
No. Electricity supplies are being
moved to half-hourly settlement, but that’s
different from every business needing a
traditional commercial half-hourly meter.
The arrangements depend on your meter type
and its capabilities.
Will my electricity supply be interrupted during MHHS migration?
The migration itself is primarily an
administrative and systems change and
should not interrupt your electricity
supply. If your supplier needs to
arrange a physical meter replacement,
they should explain any installation
requirements separately.
Does MHHS mean my standing charge will increase?
Not automatically. MHHS doesn’t
introduce a universal new standing charge.
However, electricity charges can still
change in accordance with supplier pricing,
contract terms and applicable metering
or regulated costs.
Can my supplier charge me more because of MHHS?
This depends on your contract terms, meter
type and supplier. Some suppliers may
introduce or adjust metering and data
service charges as part of the transition.
Others may absorb these costs or include
them within existing charges.
If you’re notified of additional
charges, ask your supplier to explain
the reason and contractual basis for them.
Will I receive more accurate electricity bills under MHHS?
Potentially. Businesses with compatible
smart or advanced meters may benefit from
more accurate half-hourly consumption data,
reducing the industry’s reliance on estimated
usage patterns. However, MHHS doesn’t eliminate
all estimated bills. Billing accuracy will
still depend on meter communications,
data quality and your supplier’s
billing processes.
Will MHHS affect how my electricity consumption data is used?
Potentially. MHHS increases the
use of half-hourly electricity consumption
data for settlement purposes. The arrangements
for accessing and using that data depend
on the type of meter, the customer and
applicable data protection rules.
If you’re concerned about how your
consumption data is used, contact your
electricity supplier to understand the
applicable privacy arrangements and
any available data-sharing preferences.
How WeSave can help your business
Although MHHS is a significant change for the electricity industry, most businesses won’t need to become experts in how half-hourly settlement works.
That’s where we can help.
At WeSave, we work with UK businesses of all sizes, helping them understand their electricity costs, compare competitive contracts and navigate the sometimes complicated world of business energy.
Whether you operate a small business with a single electricity meter or a larger organisation with multiple half-hourly supplies, we can help you:
- Compare business electricity prices from over 20 suppliers.
- Understand your existing rates, charges and contract terms.
- Review half-hourly electricity consumption and related costs.
- Explore fixed and pass-through electricity contracts where appropriate.
- Manage your electricity renewal or supplier switch.
- Deal directly with suppliers on your behalf throughout the duration of the contract we arrange.
And with 100% five-star reviews on Trustpilot, we’re firm believers that good old-fashioned customer service still goes a long way.
Unsure how MHHS could affect your business electricity supply?
Get in touch with WeSave for straightforward, no-obligation advice. Whether you’re simply looking for clarification or want to review your current electricity contract, we’re happy to help.
Compare Business Electricity Prices
Alternatively, call 01872 495 111 or email hello@wesave.co.uk.
Official MHHS information and further reading
For additional information about the programme and its implementation, you can refer to:
Last updated: November 2026. This guide reflects the published MHHS programme milestones and general industry guidance at the time of writing. Implementation dates and supplier-specific arrangements may change.