Latest Update 02/03/25
Market-wide Half Hourly Settlement (MHHS) is a significant upcoming industry change that will impact every electricity meter in the UK. Overseen by Ofgem, the changes aim for all electricity meters to be settled and billed on the basis of actual half hourly electricity usage, rather than manual reads and estimates.
Ofgem intends MHHS to be a key move to a smarter, more flexible energy system in the UK, playing a fundamental role in supporting customers to understand their energy usage patterns when planning for net zero. Ofgem predicts that MHHS will bring net benefits for consumers of between £1.6bn and £4.5bn by 2045.
Migration to MHHS is now scheduled to commence in late October 2025 and is expected to be completed by May 2027, at which point all electricity suppliers will be required to use half-hourly data for settlement and billing purposes. Details of the scheme are still being decided, so keep an eye on the FAQ section below, which we’ll keep updated with key information as it’s published.
How each meter will be treated during and post implementation will depend on its current meter type and setup. The current terms Meter Operator (‘MOP’, the organisation that installs and maintains your meter) and Data Collector (‘DC’, the organisation that collects your meter readings / half hourly meter data and provides it to your supplier) will cease to exist. They will be replaced by:
Two new Metering Services roles (replacing MOP) which will provide meter installation and maintenance services:
Three new Data Services roles (replacing DC) which will provide data collection services:
Previously, customers typically only appointed a Data Collector and or Meter Operator for half hourly metered supplies. However, post the migration, customers will have an option to appoint their preferred Metering Services and Data Services agents for all electricity supplies.
The key expected benefits to electricity consumers are:
Having access to half hourly data at a meter level will assist customers to better understand how electricity is being used on site.
Moving to half hourly remotely read meters over time will reduce the amount of estimated consumption used in billing.
The move to MHHS will enable more ‘dynamic’ electricity price tariffs. Where a customer can reduce energy usage or shift consumption to periods with lower demand, there will be a cost benefit as a result.
These benefits are only possible where a remotely read meter is installed. Existing manually read meters will be settled and billed half hourly, but using an estimated half hourly profile between actual reads.
The key expected risks to electricity consumers are:
Although specifics are not known at this stage, it is expected that metering and data costs will increase for existing non-half hourly metered supplies and will be closer aligned to the costs that apply for existing half hourly metered supplies (which are ~£400 per meter per annum in aggregate).
In the absence of appointing a preferred metering and data provider, customers are likely to be exposed to higher ‘off contract’ metering and data costs. To combat this and mitigate costs, LASER will arrange a bulk price for metering and data services for customers (as we do presently for half hourly supplies, with costs around half of what would apply to ‘off contract’ meters).
It is expected that sites that remain as manually read meters (e.g. existing non-AMR, non-half hourly meters) will incur a fee each time a meter reader is required to visit site (~£20-40 per reading).
In the absence of a customer appointing a preferred agent for data services, they will still be entitled to receive half hourly data from the supplier for their meters. However, we expect that services such as portal access to data and visualisation tools to help interpret data are likely to only be available where a customer or LASER appointed data agent is in place.
Although not certain at this stage, it’s possible that electricity prices may change during a pricing period where the switch to MHHS causes the electricity supply to incur alternative network charges.
The following information is provided in good faith based on information available at this time. We will continue to monitor, amend and update FAQs to capture new information as it is published.
Will existing Unmetered Supplies be impacted?
Yes, there will be impacts on all electricity supplies. For existing half hourly Unmetered supplies, we expect this may be limited to a change in the profile class of the MPAN and potentially changes to pass through costs as well. For non-half hourly Unmetered supplies (such as CCTV, car park ticket machines etc), the Unmetered Supplies Data Service provider will apply an assumed half hourly profile for settlements and billing purposes.
Will all supplies migrate to MHHS at the same time?
No, the migration window commences late October 2025 and is expected to be finalised by May 2027. Timing within this window will depend on each supplier’s readiness to make the switch and we will monitor this process with LASER’s supplies.
Are additional costs expected where a site doesn’t switch to AMR and the supplier needs to arrange manual meter reads?
Yes, although not finalised, we expect the data services provider to charge a fee (estimated at £20-40 per read) each time they need to visit a site to take a manual read.
Is a customer obliged / eligible to select their own agents for metering and data services?
There is no obligation, but a customer is eligible to appoint their own agents for both metering and data services. We expect there to be a higher ‘off contract’ charge where agents aren’t nominated, so LASER is planning to manage this under our framework to obtain a lower bulk cost for customers (as we do currently for existing half hourly supplies).
Can all existing AMR meters be remotely upgraded to half hourly?
No, it’s likely that older AMR meters cannot be remotely upgraded to half hourly. They would still transmit a meter read, but the data services provider would need to profile estimated half hourly data until the meter can be upgraded.
What happens with legacy manually read meters that aren’t upgraded prior to the migration?
These meters will remain manually read post the migration until a point where the metering can be upgraded. It’s envisaged that these supplies will incur additional costs for any manual meter reads required.
Will there be changes to electricity billing?
We envisage some changes may be required to billing formats and are working with suppliers to better understand this.
Will the existing classification of Half Hourly (HH) and Non-Half Hourly (NHH) meters exist, post MHHS?
No, under MHHS the industry will be categorised into three market segments, instead of the existing meter types. The table below illustrates the composition of each market segment.
Are there any separate elements suppliers will be required to include within bill information for the first time? For example, is it a mandatory requirement to include a breakdown of half-hourly consumption data within the bill or billing file post MHHS?
As we understand it’s not a requirement in the bill itself, however on request there will be a requirement to provide access to an online tool and provide the backing data.
Will Npower pass through metering charges and / or data services charges from third party providers on electricity billing?
Npower reserve the right to recover any pass-through charges we may receive from Metering Agents selected by a customer.
LASER will continue to monitor changes associated with MHHS and will work with our electricity suppliers, existing data collectors, and meter operators to understand and mitigate impacts on our customers.
If you have any questions on these changes or how it may impact your organisation, please use the contact us form and a member of the team will be happy to help.