Gas and Electricity Meters Explained: Main Meters, Sub-Meters & Tenant Billing

If you're managing a property with both gas and electricity supplies, understanding how each utility is metered is essential, particularly if you're responsible for tenant billing, sub-metering or specifying new metering equipment. While every property has separate gas and electricity meters, additional sub-meters may be required to accurately measure energy consumption for individual tenants or areas of a building.

This guide explains how gas and electricity meters differ, the legal requirements for billing, when sub-metering is appropriate, and the types of metering solutions available for landlords, commercial property managers and facilities professionals.

How Gas and Electricity Are Metered in the UK

Every UK property with both a gas and electricity supply has a separate meter for each utility. Gas and electricity are measured using different technologies and are supplied through separate networks, so they cannot be combined into a single meter.

Where things become more complex is when landlords or property managers need to measure energy consumption for individual tenants or specific areas of a building. In these situations, separate gas and electricity sub-meters can be installed downstream of the main utility meters to provide accurate consumption data for billing or monitoring purposes.

The same principle applies to smart meters. Gas and electricity are still measured by separate devices, although both may be installed as part of the same smart meter upgrade and communicate through a shared communications hub.

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How Gas Meters Work in the UK

A gas meter measures the volume of gas flowing through the supply pipe into a property. Readings are recorded in cubic metres (m3) on modern meters, or in cubic feet (ft3) on older imperial meters. Your energy supplier converts the volume reading to kWh for billing purposes using a calorific value and a conversion factor.

The main types of gas meter found in UK properties are:

Standard credit gas meters (the most common type, requiring manual readings)
Smart gas meters (SMETS2, transmitting readings automatically to the supplier)
Prepayment gas meters (pay before you use, topped up via key, card, or app)
Gas sub-meters (privately installed downstream of the main meter for tenant billing)

Any gas meter used for billing must be of an approved pattern under the Gas Act 1986 and hold MID approval under the Measuring Instruments Regulations 2016. Use and performance of gas meters is governed by Section 17 of the Gas Act 1986.

How Electric Meters Work in the UK

An electricity meter measures electrical energy consumed by a property in kilowatt-hours (kWh). The reading accumulates from zero as electricity is used and is read periodically to calculate consumption and bills.

The main types of electricity meter found in UK properties and commercial premises are:

Standard single rate meters (one unit rate, manual readings)
Dual rate meters (Economy 7 and Economy 10, day and night rates)
Smart meters (SMETS2, automatic readings every 30 minutes)
Prepayment electricity meters (pay before you use)
Electric sub-meters (privately installed for monitoring or tenant billing)

Electricity meters used for billing purposes must comply with the relevant requirements of the Electricity Act 1989 and the Measuring Instruments Regulations 2016. The requirement applies equally to main utility meters and privately installed sub-meters used for tenant billing.

Owen Brothers: Electric Sub-Meters for Landlords and Businesses

→ Browse All Single Phase Electric Meters
→ Browse All Three Phase Electric Meters
→ OB112 45A MID Approved DIN Rail Digital Meter
→ OB418 100A Single Phase MID Meter in IP66 Enclosure
→ Single Phase Meters in Enclosure

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Gas Meter vs Electric Meter: Key Differences

Feature	Gas Meter	Electric Meter
What it measures	Gas consumption in m3 or ft3	Electricity consumption in kWh
Typical location	Meter box outside or utility area	Meter box outside or consumer unit area
Installation authority	Gas Safe registered engineer (in most cases)	Part P registered electrician
Smart meter available?	Yes (SMETS2)	Yes (SMETS2)
Sub-metering possible?	Yes	Yes
Approval for billing?	Yes, under relevant UK metrology legislation	Yes, under relevant UK metrology legislation
Regulatory framework	Gas Act 1986 and MIR	Electricity Act 1989, Schedule 7, and MIR
Owen Brothers stock?	Metro Gas STS (prepayment)	Full range of electric sub-meters

Sub-Metering for Landlords and Multi-Occupancy Properties

Where individual tenants are responsible for their own energy costs, separate gas and electricity sub-meters provide an accurate way to measure consumption for each unit or occupancy. Installed downstream of the main utility meters, sub-meters record the energy used by a specific tenant, apartment or commercial unit, allowing landlords to allocate energy costs based on actual usage.

When reselling energy to tenants, landlords should ensure their billing arrangements comply with Ofgem's Maximum Resale Price guidance and use appropriately approved meters for billing purposes.

While Owen Brothers specialises in electric sub-metering solutions, we also supply Metro Gas STS prepayment meters for landlord applications. In addition, our remote monitoring systems can be integrated with compatible existing gas meters, enabling landlords and property managers to access meter readings remotely without replacing their current metering infrastructure.

Electric Sub-Metering: Where to Start

At Owen Brothers, we've supplied thousands of approved sub-meters to landlords, commercial electricians and facilities managers across the UK.

Based on our experience, electric sub-metering is often the natural starting point for landlords looking to monitor and allocate electricity usage.

Electric sub-meters are typically straightforward to install on existing distribution boards, provide accurate consumption data for tenant billing, and offer a cost-effective metering solution. Installation should always be carried out by a qualified electrician, with the time required depending on the property's electrical installation and the type of meter being fitted.

For most residential properties including HMOs, student lets, and small apartment blocks, a single phase meter handles the job. Larger commercial buildings, units with industrial equipment, or properties with three-phase supplies need three phase meters, potentially CT-operated if the current exceeds the meter's direct connection rating.

Owen Brothers: Electric Sub-Meters

→ Single Phase DIN Rail Meters
→ Three Phase CT Operated Meters
→ Three Phase Meters in Enclosure
→ Current Transformers Range

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Gas Sub-Metering: What You Need to Know

Gas sub-metering is possible but involves additional complexity compared to electric sub-metering. Most work on gas appliances, fittings and pipework must be carried out by a Gas Safe registered engineer, and gas sub-meters should be approved in accordance with the relevant UK metrology requirements for billing purposes.

For properties with communal gas supplies serving multiple tenants, gas sub-metering allows the landlord to attribute gas consumption to individual units. Owen Brothers stock the Metro Gas STS pre-payment meter for landlord gas metering applications.

Owen Brothers: Gas Prepayment Meter

→ Metro Gas STS Prepayment Meter (METGAS)

Smart Meters vs Sub-Meters: What's the Difference?

Smart meters are installed by energy suppliers to measure a property's overall gas or electricity consumption and automatically send meter readings for billing purposes. They do not replace privately installed sub-meters used to monitor or allocate energy consumption within a building.

For landlords and commercial property managers, smart meters and sub-meters often work alongside each other. The utility smart meter records total energy consumption for the property, while privately installed sub-meters measure usage for individual tenants, departments or units. This provides accurate consumption data for monitoring and, where appropriate, tenant billing.

Owen Brothers supplies a range of approved electric sub-meters and prepayment gas meters, together with remote monitoring solutions for compatible metering systems, helping customers manage energy usage more effectively.

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The Legal Framework for Gas and Electric Meters in the UK

The legal requirements for gas and electric meters share the same foundation but are governed by separate primary legislation.

Gas meters used for billing are subject to the Gas Act 1986 and the relevant UK metrology legislation. Any gas meter used for billing must be of an approved pattern, and since 2006, new gas meters are also approved under the Measuring Instruments Regulations 2016.

Electricity meters used for billing are subject to Schedule 7 of the Electricity Act 1989 together with the Measuring Instruments Regulations. Since 2006, new electricity meters are also approved under this framework.

For landlords, the key practical point is that meters installed for billing purposes should meet the relevant UK approval requirements under the Measuring Instruments Regulations 2016. Using a non-approved meter for billing purposes may result in disputes over the accuracy of charges and could lead to regulatory enforcement. Using an unapproved meter may also make it more difficult to demonstrate the accuracy of charges if they are disputed.

Owen Brothers: Approved Meters for Billing

→ Browse All Single Phase Meters
→ Browse All Three Phase Meters
→ Metro Gas STS Prepayment Meter (METGAS)
→ Metro 80A Single Phase Pre-Payment Electric Meter

Maximum Resale Price Rules for Gas and Electricity

Whether you are sub-metering gas, electricity, or both, Ofgem's Maximum Resale Price guidance applies to both utilities. Under Ofgem's Maximum Resale Price guidance, landlords who resell gas or electricity should not charge more than they pay their supplier, including unit rates, standing charges, and VAT, subject to any applicable legislation and guidance.

Ofgem opened a Call for Input on the Maximum Resale Price rules in October 2025, the first formal review in over 20 years. Landlords should monitor Ofgem's website for any changes to the current guidance as this review progresses.

Prepayment Options for Gas and Electricity

For landlords who want tenants to pay in advance for both gas and electricity, prepayment sub-meters are available for both utilities. Owen Brothers stock the Metro range of prepayment meters for both gas and electric sub-metering applications.

Smart prepayment systems now allow tenants to top up online or via mobile app, removing the need for physical tokens or cards. The landlord receives a portal showing real-time balances and consumption per unit, and monthly payments are transferred automatically.

Owen Brothers: Prepayment Meters for Gas and Electricity

→ Metro Pre-Payment Meters Range
→ Metro 80A Single Phase Pre-Payment Electric Meter (MET001)
→ Metro Gas STS Prepayment Meter (METGAS)

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Remote Monitoring for Gas and Electric Sub-Meters

For landlords managing multiple units or properties, manually reading gas and electric sub-meters can be both time-consuming and impractical. Owen Brothers supplies industrial-grade 4G modems with multi-network SIM cards that connect compatible metering and monitoring devices to the OBmeters.com online portal. This allows meter data to be transmitted securely and viewed remotely from a laptop, tablet or smartphone, giving landlords, facilities managers and commercial property owners convenient access to consumption data without the need for site visits.

Owen Brothers: Remote Monitoring

→ Remote Monitoring Overview
→ OB4373 Rogowski Monitoring Kit with 12 Months Remote Access

Frequently Asked Questions

Do gas and electric meters need to be in the same location?

No. Gas and electricity meters can be located in different places on the property. In most UK homes and commercial buildings they are both located in an external meter box or utility cupboard, but they are separate devices and do not need to be adjacent.

Can I install a gas sub-meter myself?

No. Most work on gas appliances, fittings and pipework must be carried out by a Gas Safe registered engineer. Electric sub-meters must be installed by a qualified electrician.

Do I need separate approval for gas and electric meters used for billing?

Approval is required for both gas and electric meters used for billing. The approval process is separate for each meter type, and you should confirm the relevant approval status for each meter individually before purchase. Owen Brothers' MID-approved meters are clearly labelled on product pages.

Can I charge tenants more than I pay my supplier for gas or electricity?

Under Ofgem's Maximum Resale Price guidance, landlords who resell gas or electricity should not charge more than they pay their own supplier, including unit rates, standing charges, and VAT, subject to any applicable legislation and guidance.

Does Owen Brothers supply gas meters as well as electric meters?

Owen Brothers' primary range focuses on electric sub-metering, including single phase, three phase, CT operated, Rogowski coil, and remote monitoring products. Owen Brothers also stock the Metro Gas STS prepayment meter for gas sub-metering applications.

What are the consequences of using a non-approved meter to bill a tenant?

For landlords and businesses, it is important that any meter used for billing complies with the relevant UK approval requirements. Using a non-approved meter could result in regulatory action and may allow tenants or customers to dispute charges based on the meter readings.