This article covers what counts as a relevant heat network and the key exemptions, the difference between the operator and supplier roles, and how registration works depending on how many entities are involved, what Ofgem asks for, and what happens once you have registered.
Key Highlights
What Counts as a Relevant Heat Network?
A heat network is any system that distributes a liquid or gas to transfer thermal energy for heating, cooling or hot water. Only "relevant" heat networks fall within Ofgem's regulation, and there are two categories either a district heat network or a communal heat network.
A district heat network supplies heating, cooling or hot water to two or more buildings, sometimes across a whole site or development.
A communal heat network supplies a single building that has been divided into separate premises. A residential block of flats on shared heating is the standard example, but the definition also catches buildings with non-domestic tenants on the same system.
Who are Exempt from the Heat Network Regulation
Not every heat network that meets this definition has to register. Ofgem's guidance sets out exemption from the regulation for three specific circumstances, and no application is needed meaning the exemption simply applies, or it doesn't.
- An House in Multiple Occupation (HMO) consisting of a single house or building with shared kitchen or bathroom facilities and a shared heating system is exempt outright. The regulations treat it as not having separate premises. That exemption does not extend to converted blocks of flats with self-contained units, which remain in scope if they share a heating system.
- A converted building with a shared heating system of domestic capacity is also exempt, but only where it is supplied by no more than one source appliance of 45 kilowatts or less.
- Third-party waste-heat producers such as data centres and wastewater treatment sites are generally not carrying out a regulated activity in their own right, even where their waste heat feeds a regulated network downstream.
Who Needs to Register for a Heat Network?
Operation means controlling the transfer of thermal energy on the network in practice, having substantial control over the long-term reliability, efficiency and compliance of the system, including authority over major investment decisions such as upgrades or expansions. Ownership of the physical assets is a signal, not the test. The operator is whoever has sufficient control over the assets needed to comply with the regulatory framework.
Supply means holding the commercial relationship with customers setting charges, issuing bills, handling customer service and resolving complaints typically underpinned by a heat supply agreement.
A single entity commonly does both, in which case that entity registers for both roles in one submission. Where roles are split, the freeholder is typically expected to act as operator, retaining overall responsibility for the communal system, unless a Right to Manage company or Residents' Management Company has taken on that role, in which case operator status may shift to the RTM or RMC. Every party needs to assess its own position against these definitions rather than assume the answer from who happens to hold the freehold.
The Heat Network Registration Deadline: 27 January 2027
The regulatory framework has moved in stages, and the dates are easy to conflate.
Date | What happens |
|---|---|
1 April 2025 | The initial period begins. Anyone operating or supplying a relevant heat network from this date onward is automatically "deemed authorised" under regulation 27. No application needed. |
27 January 2026 | The general authorisation conditions (consumer protection, financial resilience, reporting) come into effect. Authorised persons must comply with these regardless of whether they have registered. |
27 January 2027 | End of the "first part of the initial period" (regulation 26). All operators and suppliers with deemed authorisation must have completed registration by this date. |
Registration is not authorisation, and it is not an assessment. Registering a heat network does not change your authorisation status. It is the separate, mandatory step of formally telling Ofgem who you are, what you do, and providing baseline compliance information. Ofgem's digital service for heat networks regulation opened for registration during 2026; there is no reason to wait until the deadline, and doing so leaves no room to resolve split-registration or multiple-operator complications discussed below.
How Heat Network Registration Actually Works?
The process of registration depends on how many entities are involved in your heat network.
1. Heat network registration as a single entity
2. Registration of heat networks with split regulatory responsibility
3. Registration of heat networks with multiple operators
What Information Does Ofgem Ask for at Registration of Heat Network?
Organisation-Level Information
Network-Specific Information
Who | What they provide |
|---|---|
Operator | The network's location, how many buildings it supplies, the number of embedded communal networks and who's responsible for them (for district networks), the energy source and technology used, and the network's heating capacity |
Supplier | Customer type (domestic or non-domestic), how many of each, and whether any non-domestic customers count as "small business" or "microbusiness" consumers |
Further requirements
Networks With a Shorter Process
Self-supply and industrial heat networks, for example hospital or campus schemes, or networks entirely serving an industrial process, still must register, but sections B and C of the general authorisation conditions don't apply to them.
Why Your Heat Network Accounts Are the Hardest Part of Registration
If service charge income, energy costs and any reserve funds for the heat network are not clearly separated and reconciled in your heat network accounts, you cannot produce credible financial resilience figures on request, and you cannot demonstrate that a continuity plan is genuinely "fit for purpose" rather than a document nobody has tested. This is also where a backlog matters most: if billing records held by a managing agent or metering contractor are incomplete or inconsistent with your accounts, the supplier-side registration fields (customer numbers, complaints history) become guesswork rather than fact.
What Happens After You Register for Heat Network
Heat network registration is not the end of the obligation, and it is unlikely to be your only interaction with Ofgem on this network.
Under regulation 12 of the 2025 Regulations, Ofgem must publish and regularly update a public list of authorised persons, including the regulated activities they undertake and the geographical location of the network. Your registration becomes a matter of public record.
You must continue to comply with all relevant authorisation conditions before and after registration. Registering does not pause your consumer protection obligations, which have applied since 27 January 2026 regardless of registration status.
Ongoing regular data reporting is required under authorisation condition A9, with the detailed frequency and content set out in Ofgem's regular data reporting guidance. At the time of writing, that guidance is being finalised following consultation, and requirements will come into effect once published but the reporting obligation itself is confirmed, so build it into your compliance calendar now rather than waiting for the final specification.
Ofgem also expects regulated parties to engage in future with the Heat Network Technical Assurance Scheme (HNTAS) as part of ongoing compliance. HNTAS requirements have not yet been finalised, so treat this as a scheme to monitor rather than an active obligation today.
What Happens If You Don't Register for Heat Network?
Failing to register by 27 January 2027 leaves you in breach of a mandatory obligation under regulation 26 of the Heat Networks (Market Framework) Regulations 2025. Operating or supplying a relevant heat network without meeting your authorisation obligations is a criminal offence, and Ofgem can impose financial penalties of up to the higher of 10% of turnover or £1,000,000 under regulation 45 of the Regulations.
Beyond the direct penalty risk, an unregistered network sits outside Ofgem's published list of authorised persons, visible by its absence to anyone checking, and any consumer complaint received before you register is likely to draw Ofgem's attention to the compliance gap directly.
Conclusion
The 27 January 2027 deadline of heat network registration is fixed, but the scope question is not always obvious, and the information Ofgem wants goes further than most operators expect. Anyone with communal heating on their portfolio should establish now whether they are in scope, which role they hold, and whether their financial and billing records could support a registration submission if asked.
If you manage communal heating across one or more schemes and are not confident your accounts would support a registration submission, our Heat Network Accounts team can review where you stand before the deadline does it for you.
Get Your Heat Network Accounts in Order Before You Register
Frequently Asked Questions
The main change is that Ofgem became the statutory regulator of heat networks under the Heat Networks (Market Framework) Regulations 2025, made under the Energy Act 2023. Anyone operating or supplying a relevant heat network is now required to hold authorisation, comply with a set of consumer protection and financial resilience conditions, and complete registration with Ofgem by 27 January 2027. This is a new framework, separate from anything previously required under general property or tax law, and it applies whether or not you've had any prior contact with Ofgem.
Think of scale: a communal network stays within one building split into separate units, like a block of flats sharing a boiler, while a district network reaches across two or more buildings, sometimes an entire estate or mixed-use site. A single district scheme can also have smaller communal networks sitting inside it, each one authorised in its own right rather than being covered by the district network's registration.
Only in specific circumstances. If your managing agent is acting as the operator or supplier in their own right, they register in that capacity. Where there are multiple operators, one can be nominated to register and correspond with Ofgem on behalf of the others, provided that agreement is genuinely reached between the parties. A managing agent cannot simply register for a freeholder who has not delegated that role to them.
It's likely to affect you if anyone, whether staff, a director, or an external adviser, has real say over how your heat network is run. Ofgem wants confirmation that person has been checked and is considered fit to hold that influence, not just a job title. You give this confirmation once every three years rather than at every registration, so if your organisation already has a current one on file, this step is simply satisfied rather than repeated.
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