Business Energy Tariffs Explained: Fixed, Flexible, Green & Pass-Through (2026)

Choosing a business energy tariff comes down to one core decision: do you want price certainty, or do you want to ride the wholesale market? Everything else — fixed terms, flexible purchasing, pass-through structures, green certificates, no-standing-charge deals — flows from that choice. This guide explains every business energy tariff type available in the UK in 2026, who each one genuinely suits, and the traps hidden in the small print.

Unlike households, businesses have no price cap and no default tariff protections. The contract you sign is the deal you get, usually with no cooling-off period. That makes understanding the tariff structures worth ten minutes of any owner’s time — because the difference between the right and wrong structure for your usage pattern is measured in thousands of pounds over a contract term.

Fixed-rate tariffs — the SME default

A fixed tariff locks your unit rate (pence per kWh) and standing charge (daily fee) for the whole term — typically 1, 2, 3, 4 or 5 years. Wholesale prices can double mid-term and your rate doesn’t move. Equally, if the market falls, you’re committed until renewal.

Who it suits: the overwhelming majority of small and medium businesses. If energy is a cost you want to budget, not a market you want to trade, fix it and move on. Roughly nine in ten SME contracts are fixed for good reason.

What to watch:

• Fixed price ≠ fixed bill. Your bill still varies with how much you use — only the rates are locked.
• Term-length timing. Fixing for longer buys certainty, but fixing a 5-year deal at a market peak hurts. When wholesale prices are historically low, longer terms are attractive; when they’re elevated, shorter terms preserve flexibility.
• “Fully fixed” vs “fixed with pass-through clauses”. Some contracts let the supplier pass through increases in non-energy costs (network charges, levies) even during a fixed term. Check whether your fix covers 100% of the rate or only the wholesale element.

Variable and flexible tariffs — for market-watchers

A variable tariff tracks the market — your rate can move during the contract, up or down, per the supplier’s published mechanism. True flexible purchasing goes further: larger businesses buy their forecast consumption in tranches on the wholesale market across the year, locking portions when prices dip.

Who it suits: larger consumers (typically 1 GWh+ per year) with the appetite and time — or an energy consultant — to manage purchasing decisions actively. Done well, flexible buying beats a fixed price over the long run. Done passively, it just means unmanaged risk.

What to watch: volume tolerances and reconciliation clauses. Flexible contracts often commit you to consuming within a band of your forecast; significant under- or over-consumption triggers adjustment charges.

Pass-through tariffs — transparency with moving parts

A pass-through contract splits your bill in two: the wholesale energy cost (which may be fixed) and the non-energy costs — network/distribution charges, balancing costs, policy levies — which are passed through at cost as they change. Around 60% of a typical electricity bill is non-energy cost, so this is a substantial moving element.

Who it suits: half-hourly metered and larger sites that want a lower headline rate and can tolerate some bill movement. Pass-through deals are usually priced cheaper than fully-fixed ones because the supplier carries less risk.

What to watch: budgeting. Your finance team needs to understand that “fixed” applies to the commodity only. If a predictable monthly cost matters more than squeezing the last percent, choose fully fixed instead.

Deemed and out-of-contract rates — the ones to escape

Not really a tariff you choose — a tariff that happens to you. If you move into premises without agreeing a contract, or let a fixed deal lapse, you’re billed on deemed or out-of-contract rates, typically 30–80% above market. You can leave at any time with up to 28 days’ notice and no exit fee. If any of your meters are on deemed rates, fixing that is the single biggest saving available to your business — our deemed contract escape guide walks through it step by step.

Green and renewable tariffs

Green tariffs supply electricity matched to renewable generation, evidenced by REGO certificates (Renewable Energy Guarantees of Origin), or gas offset/backed by biomethane and carbon credits. Competition has compressed the “green premium” to little or nothing on many deals in 2026 — it’s common to find REGO-backed fixed tariffs within a fraction of a penny of standard ones.

Who it suits: any business whose customers, tenders or supply-chain questionnaires ask about sustainability. If you report Scope 2 emissions, a REGO-backed tariff is the simplest lever you can pull.

What to watch: greenness varies. “100% renewable electricity backed by REGOs” is standard; deeper options (direct power purchase agreements, time-matched renewable supply) cost more but carry more weight in serious ESG reporting.

No-standing-charge tariffs — niche but real

A small number of suppliers offer tariffs with no daily standing charge, recovering their costs through a higher unit rate instead. The arithmetic only works for genuinely low-usage or intermittently-used sites — think seasonal businesses, rarely-used storage units, or holiday operations closed half the year. For a typical always-on business, the inflated unit rate costs more than the standing charge it replaces.

Rule of thumb: below roughly 5 kWh/day of electricity usage, no-standing-charge deals are worth pricing; above it, they rarely win.

Multi-site, half-hourly and water — the special cases

• Multi-site businesses can bundle all meters into one “basket” contract with a single end date (co-terminus), one negotiation and one renewal. Easier admin, more buying power.
• Half-hourly (HH) supplies — mandatory for sites with peak demand over 100 kW — are priced individually against your actual half-hourly consumption profile, and come with separate Meter Operator (MOP) and data agreements worth comparing in their own right.
• Water has been open to competition for all English businesses since 2017 — and is often quoted alongside energy in one exercise, which is exactly how our quote form handles it.

So which tariff should your business choose?

A simple decision path covers most cases:

• Most SMEs: fully fixed, 1–3 years, length judged against where the market sits at signing.
• Low-usage or seasonal sites: price a no-standing-charge option against a standard fix.
• ESG-conscious businesses: REGO-backed fixed — the premium is now minimal.
• Large consumers (1 GWh+): consider flexible or pass-through with proper purchasing support.
• Anyone on deemed rates: fix immediately; everything else is secondary.

Whatever the structure, the rate you’re offered varies meaningfully between suppliers for the same business on the same day — which is why comparing the whole market matters more than perfecting the tariff theory. Our business energy comparison guide shows current price ranges, and a free quote shows your actual numbers in about 60 seconds. When you do sign, remember to file your VAT declaration if you qualify for the reduced rate — see our VAT on business energy guide.

Frequently asked questions

What is the most common business energy tariff?

The fixed-rate tariff. The large majority of UK SME contracts fix the unit rate and standing charge for 1–3 years, prioritising budget certainty over market exposure.

Can my fixed business energy price change during the contract?

On a fully fixed contract, no — both unit rate and standing charge are locked for the term. Some contracts fix only the wholesale element and pass through changes in network charges and levies, so check which type you’re signing.

Are green business energy tariffs more expensive?

Usually only marginally, and sometimes not at all. Competition has pushed REGO-backed renewable tariffs to within a fraction of standard prices on many 2026 deals. Deeper green products like corporate PPAs cost more.

Should I fix for 1 year or 3 years?

It depends where wholesale prices sit when you sign. Longer fixes are attractive when the market is low; shorter terms preserve flexibility when prices are elevated. A whole-market comparison will price both so you can judge the premium for certainty.

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