What does a compliant heat network bill need to include?

Under Authorisation Condition B6, heat network bills must include the tariff applied, consumption data, the billing period, contact details for complaints, and signposting to the Energy Ombudsman. Ofgem's Model Compliant Bill guidance sets out the required layout and information fields in detail.

What is the back-billing rule for heat networks?

Under Authorisation Condition B7, heat network operators cannot back-bill consumers for more than 12 months where the error was not the consumer's fault. This mirrors the back-billing protections that exist in gas and electricity supply and is a new obligation introduced by the 2025 Regulations.

Do heat network operators need to provide accessible bills?

Yes. Operators must be able to provide bills in accessible formats for consumers who need them, including those on the Priority Services Register. This includes large print and other formats as appropriate to the consumer's needs.

What metering is required for heat network billing compliance?

Bills must be based on actual metered consumption where meters are installed. Authorisation Condition B6 and the TR1 metering standards set out requirements for meter accuracy, calibration, and compliance. Operators should maintain a metering compliance register to demonstrate ongoing compliance.

Can heat network operators use estimated bills?

Estimated billing is permitted where actual meter readings are not available, but operators must take steps to obtain actual readings and must clearly indicate where a bill is estimated. Persistent estimated billing where metering is available is likely to attract Ofgem scrutiny.

Heat network billing: Ofgem’s mandatory bill rules (2026)

Key points

Every bill sent to a heat network consumer must include specific mandatory fields set by Ofgem
Operators who bill directly need a compliant bill layout
Operators using energy billing software need to verify their system’s output meets every requirement

Billing is where most operators first encounter a compliance gap they did not expect. The bill you have been sending consumers for years almost certainly does not meet Ofgem’s requirements – and under the Market Framework Regulations 2025, billing transparency is a core authorisation condition. Every bill must include specific mandatory fields. Missing even one is a compliance failure.

This guide covers what must appear on every bill and explains the two approaches operators typically take, depending on whether they bill directly or use energy billing software.

Heat meter display showing consumption readings in MWh

What must appear on every bill

Ofgem’s model bill requirements are specific. Every consumer bill must include: your name and contact details as the operator, the billing period, meter readings (opening and closing) with total consumption, the applicable tariff rates with standing charges separated from variable charges, the total amount due with payment terms and due date, information about the complaints procedure including the right to escalate to the Energy Ombudsman after eight weeks, and a reference to the Priority Services Register.

The intent is that heat network consumers receive the same billing transparency as gas and electricity customers. These are the fields the billing condition sets out. A bill that omits any of them does not meet the condition as written; check Ofgem’s current guidance for how it applies to your network.

Approach 1: Operators who bill directly

Many smaller operators – particularly those running 1–3 networks – produce bills themselves using office software, accounting software, or simple invoicing tools. These operators need a compliant bill layout that includes every mandatory field in the right format.

The Model Compliant Bill provides this. It includes four files: a compliance checklist (fillable, to audit your bill against every requirement), a worked example showing a completed Greenfield bill, a visual layout showing where each element should appear, and a layout example with realistic values. At £175 individually or included in the Compliant Bundle (£895). For a full bundle comparison, see the pricing page.

Common gaps in existing bills. Missing or incomplete complaints escalation wording (the Energy Ombudsman reference is often absent), no PSR reference, unclear tariff breakdowns where standing charges and variable charges are not separated, and missing payment terms or due dates.

Approach 2: Operators using energy billing software

Larger operators and those with managed heat networks often use specialist energy billing software – platforms such as Guru Systems, Utiligroup (now part of Ensek), Insite Energy, or Switch2. These systems generate bills automatically from meter data and tariff configurations.

If you use billing software, your bills may already include most mandatory fields. However, “most” is not enough for Ofgem authorisation. You need to verify that every mandatory field appears, that the complaints procedure wording meets requirements, and that the PSR reference is included.

Working with your software provider

If your bill audit reveals gaps, raise them with your software provider. Most billing platforms allow customisation of bill templates – but the configuration is your responsibility. This is a point many operators miss: Ofgem holds the operator accountable for bill compliance, not the software vendor. If your platform produces a non-compliant bill, that is your problem, not theirs. Document the changes you request and verify the output once implemented.

The same point applies to the evidence underneath the bill. Whoever generates it, the accuracy record stays your responsibility, and a bill is only as defensible as the meter behind it. If you would rather hold that evidence as a live record than a spreadsheet, AXIS is a metering and billing compliance platform that keeps meter calibration status and billing complaints on the same record. It does not produce bills; it holds what they rest on.

Consumer protection under Ofgem heat network regulation

Heat network billing agents and where responsibility sits

Some operators go a step further than software and hand the whole function to a heat network billing agent: a third party that collects meter reads, calculates charges, issues the bills, and often fields the first line of consumer queries. It is a sensible arrangement for an operator without a billing team, and it is common in managed residential portfolios.

It changes who does the work. It does not change who answers to Ofgem. The authorisation conditions bind the operator, so if an agent issues a bill missing a mandatory field, applies a tariff incorrectly, or lets a complaint run past the required timescale, that is the operator’s breach. Outsourcing the task does not outsource the obligation, and an agent’s assurance that everything is handled is not evidence.

What that means in practice is that you need the records out of the agent, not just the service from them. Three things are worth writing into the contract: that the agent supplies the meter accuracy and calibration data behind the charges, that bill templates are auditable against the mandatory fields and changes are notified to you, and that complaints are reported to you with their dates so your own complaints record is complete. Ask for them at contract stage. Asking for three years of history after Ofgem opens a query is a different conversation.

Which approach is right for you?

If you produce bills yourself (spreadsheets, accounting software, manual invoices) – use the Model Compliant Bill as your bill layout and compliance reference.

If you use energy billing software – use the Model Compliant Bill checklist to audit your existing bills. If they pass every field, you may not need the layout. If they have gaps, either reconfigure your software or use the layout as a compliant alternative.

Getting started

Pull a recent bill – either one you produced or one generated by your software. Check it field by field against the mandatory requirements listed above. If anything is missing or unclear, fix it before your authorisation application. This is one of the easier conditions to satisfy, but also one of the easiest to overlook.

For the full regulatory context, see Ofgem’s consumer protection guidance for heat networks. Billing transparency is one of several consumer protection conditions – our authorisation conditions guide covers the full set.

How to produce a compliant heat network bill