Here, Stuart Wilcox, Head of Critical Infrastructure at FirstPort, explains the most common methods being used to ensure fair, more transparent billing for customers on heat networks, and how charges are likely to evolve under changing technical and regulatory standards.

With new regulation and oversight from Ofgem, the landscape is shifting – bringing greater transparency, accountability, consistency, and consumer protection. While this new framework will improve the way heating is provided and paid for, it is also important that consumers understand the key components that make up the service they receive and how this is billed as new systems roll out.

Heat tariffs and Heat Supply Agreements (HSAs)

Modern heat networks increasingly rely on Heat Supply Agreements, which set out the commercial relationship between the heat supplier and the customer. As Ofgem regulates the sector, HSAs are expected to become the standard billing method, to ensure greater consistency and transparency.

Heat tariffs under HSAs are normally split into two elements: a standing charge and a variable (consumption-based) charge.

The standing charge covers the fixed costs of delivering heat – costs that exist regardless of how much heat an individual customer uses, which typically includes metering costs, billing and administration, insurance, auditing, VAT and operational and routine maintenance, as well as sinking fund contributions for lifecycle replacement of major equipment.

These costs ensure the network can operate safely, reliably, and sustainably over the long term.

The variable charge is based on how much heat is actually used. It can go up or down based on things like the cost of gas (if your network uses it), how efficiently the energy centre and network are running, plus factors such as VAT and any costs linked to managing debt.

Although this charge typically fluctuates more than the standing charge because it is influenced by wholesale energy prices and network performance, it will remain stable for the duration of the tariff period, as the gas rates are fixed for one year.

How service charge billing works

Before HSAs became common – and prior to today’s metering technology and standards – many networks charged residents for heat through their service charge, particularly in older buildings with leases before 2020 and where no consumer meters have been installed. These service charges often bundled heat costs together with other building services.

This method under current arrangements, remains permissible by Ofgem for both metered and unmetered networks, however, Ofgem is currently consulting on proposals that would eventually require heat networks to unbundle individual heat charges once metering is installed, in accordance with further phased legislation under the HNTAS (Heat Network Technical Assurance Scheme) technical standards.

Metered vs. unmetered networks

The way that network usage is measured and billed has been the subject of stringent review. Historically, the specified method has typically depended on whether a development’s network is metered or unmetered.

When networks are metered, costs can be simply allocated based on individual consumption as heat meters are installed.

On an unmetered heat network, homes don’t have individual heat meters to measure how much heating or hot water each household actually uses. Because of this, suppliers can’t bill residents based on real consumption. Instead, they estimate costs using a proxy, such as the size of the property, the number of bedrooms, or the total floor area – on the assumption that larger homes generally require more heat.

This approach is common on older heat networks where meters weren’t originally installed. However, as UK regulation evolves, new HNTAS standards are expected to require suppliers to install meters at defined points in the system, use metering data to bill customers based on actual usage, separate or ‘unbundle’ heat costs from other building charges, and improve performance monitoring, reporting, and overall transparency.

Under new technical standards, more networks will adopt direct metering supported by an independent metering and billing agent, whose central role is to collect, verify, and manage consumption data to ensure accuracy and accountability, providing residents with clearer insight into how energy is measured and charged. As these requirements come into force, this will enable billing to shift from proxy-based estimates to charges based on verified real usage – making costs clearer, fairer, and more accurate for residents.

A more transparent, fair heat market

As the operation of heat networks enters a period of transition – and becomes an increasingly important part of the UK’s low‑carbon future – the way customers are billed will change alongside new regulations. This shift can feel complex, but the new framework is designed to provide greater clarity, backed by stronger commitments and accountability. As further details are confirmed, keeping customers informed will remain a priority, ensuring everyone understands what these changes mean for them.

Whether through modern Heat Supply Agreements or legacy service charge arrangements, the goal remains the same: to deliver affordable, reliable heat with transparency and fairness at the core.