Switch to a green gas tariff in the UK (and could you save?)

If you want lower bills

Prioritise the unit rate and standing charge, then check fees and contract length. Green credentials shouldn’t hide a higher price.

If you want meaningful “green” impact

Look for tariffs that support biomethane via certificates or blend claims, and read how evidence is provided (e.g., certificates, annual reporting).

If you’re on a tight budget

A cheaper standard tariff may beat a premium green option. You can still cut emissions by lowering gas use (thermostat, insulation, boiler controls).

Most UK homes receive natural gas through the national distribution network. A “green gas” tariff usually means your supplier does one (or more) of the following:

Biomethane matching (certificates)

The supplier buys certificates showing a quantity of biomethane (from anaerobic digestion, landfill gas, etc.) has been injected into the UK gas grid, matching your use.

Carbon offsetting

The supplier funds projects claimed to reduce/remove emissions elsewhere. Quality varies; look for clear project info and verification.

Blends or “up to” claims

Some tariffs state an “up to X% green gas” approach across a portfolio. Check what percentage is guaranteed and how it’s evidenced.

If you rent, you can usually switch supplier if you pay the bills — but check your tenancy agreement and whether bills are included.

Decision checklist: who green gas switching suits

• You can pay by Direct Debit (often widest access to deals)
• You’re comparing the total estimated annual cost (unit rate + standing charge)
• You’ve checked whether the tariff uses biomethane matching, offsets, or both
• You’re happy with any contract length and possible exit fees
• You’re switching at least a few weeks before a fixed deal ends (to avoid rolling onto a pricier tariff)

Who it may not suit (or needs extra care)

• Very low gas users: a higher standing charge can outweigh any unit-rate saving
• Prepayment meters: fewer tariffs; some switches require meter changes
• In debt to your current supplier: switching may be restricted (rules vary)
• Short-term tenants: exit fees may make fixed deals poor value
• Anyone relying on “100% green” wording: always read what the claim refers to and how it’s backed

1) Standing charge surprises

Some tariffs advertise a low unit rate but have a higher standing charge. For smaller homes or warmer properties, the standing charge can dominate your bill.

2) Exit fees on fixed tariffs

If you leave early, you may pay an exit fee per fuel. Check the terms if you may move home, change meter, or switch again soon.

3) “Green” claims that mean offsets only

Offsets can be legitimate, but quality varies. If you want biomethane support, look for explicit biomethane matching and evidence (not just “carbon neutral”).

Two realistic scenarios (with numbers)

These examples show how “green gas” can be cheaper or more expensive depending on rates and standing charges. They’re illustrative only, not a prediction.

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Written by

EnergyPlus Editorial Team

Reviewed by

Energy Specialist (UK domestic energy)

Last updated

April 2026

Our methodology (plain English)

When we say a switch could save money, we mean: a household may find a tariff with a lower estimated annual cost than their current tariff, based on:

• Unit rate (p/kWh) and standing charge (p/day)
• Payment method (e.g., Direct Debit vs other)
• Meter type eligibility (credit vs prepay; smart meter where required)
• Tariff structure (fixed/variable; exit fees; minimum terms)
• Regional availability (tariffs vary by postcode)

Limitations: quotes are estimates and may change; your actual bills depend on usage, temperature, home efficiency, meter reads/estimates, and supplier billing practices. “Green gas” definitions vary by supplier; we encourage users to read tariff documents.