Choosing a business energy tariff sounds simple… until you realise it can quietly add thousands to your annual costs.
One minute you’re signing what looks like a straightforward contract. The next, wholesale markets spike, your competitor’s bills jump 30%, and you’re either feeling very smart… or very frustrated.
That’s the reality of fixed vs variable business energy.
At first glance, the difference seems small:
A fixed tariff locks in your unit rate for 1–5 years.
A variable tariff moves up and down with the market.
But that single decision affects your budgeting, your cash flow, your pricing strategy, and ultimately your profitability.
Think of it like this:
Fixed = putting your energy costs on cruise control.
Variable = riding the market rollercoaster (which can be fun… or expensive).
There’s no universal “best” option. The right choice depends on how much energy your business uses, how comfortable you are with risk, and what’s happening in the market when you sign.
In this guide, we’ll break down:
Exactly how business energy tariffs work
What “fixed” really fixes (and what it doesn’t)
The real pros and cons of variable pricing
Which option makes more sense for UK businesses in 2026
And how to avoid the costly mistake of ending up on an overpriced standard variable tariff
By the end, you’ll know whether your business needs stability, flexibility, or a smarter strategy altogether.
Let’s get into it.
What Is the Difference Between a Fixed and Variable Business Energy Tariff?
A fixed energy tariff locks in your unit rate and standing charge for the duration of the contract, typically 1 to 5 years, so your rate per unit of energy stays the same regardless of what happens in the wholesale energy market. A variable tariff, by contrast, moves up or down in line with market conditions, meaning your energy bill can change from month to month.
This single distinction has significant financial consequences for every business. Choosing wrong costs money. Choosing right buys stability or flexibility, depending on what your business actually needs.
How Business Energy Tariffs Work: The Basics
Before comparing fixed vs variable, you need to understand what you’re actually paying for on a business energy bill.
Unit Rate — the price you pay per unit of energy (measured in pence per kWh). This is the biggest variable in your energy cost calculation. On a fixed rate tariff, this number doesn’t change. On a variable tariff, it can shift monthly.
Standing Charge — a fixed daily charge (in pence per day) that covers the cost of supplying energy to your premises regardless of how much electricity you use. Even on a variable tariff, the standing charge is often semi-fixed, though it can still be revised by your supplier.
Unit Rates and Standing Charge Together determine your total energy cost. A low unit rate with a high standing charge can actually cost more than a slightly higher unit rate with no standing charge, depending on how much energy you use.
Exit Fee — a penalty charge applied if you leave a fixed rate contract before it ends. Exit fees are common on fixed business energy contracts and can run into hundreds or thousands of pounds depending on the supplier and the duration of the contract remaining.
Fixed Business Energy Contracts Explained
A fixed business energy contract means your supplier agrees to charge you the same unit rate for a set period, usually between 12 months and 5 years. The energy price is agreed upfront when you sign the contract.
What “Fixed” Actually Fixes and What It Doesn’t
This is where many businesses get caught out. A fixed rate tariff fixes your unit rate and usually your standing charge. It does not fix:
- Your total energy bill (that depends on how much energy you use)
- Government levies and taxes, which can still change mid-contract
- Network distribution charges in some contracts always check the small print
So when energy experts say “fixed,” they mean the wholesale cost component is locked. Your bill can still vary if your energy usage changes. A fixed tariff means your rate is stable, not that your bill is identical every month.
Advantages of a Fixed Rate Business Energy Tariff
Budget certainty. Knowing your unit rate in advance makes financial forecasting far more straightforward. For businesses with tight margins or seasonal cash flow, this peace of mind has real commercial value.
Protection from price rises. If wholesale energy prices increase after you lock in, your business is insulated. During periods of energy market volatility, like the sharp rises seen in 2021–2023, businesses on fixed contracts avoided enormous cost increases that hit those on variable tariffs hard.
Easier energy comparison. Because the rate is clear and stable, comparing business energy suppliers is simpler when you’re shopping for fixed deals.
Disadvantages of a Fixed Rate Business Energy Tariff
You won’t benefit if prices fall. If global energy prices drop significantly during your contract period, you’re still paying the locked-in rate. You cannot take advantage of lower wholesale costs.
Exit fees can be punishing. If your business circumstances change, you move premises, scale down, or find a better deal, leaving a fixed contract early typically triggers an exit fee.
Rates at signing reflect the market at that moment. If you lock in during a period of high energy prices, you may end up overpaying relative to where the market moves.
Variable Business Energy Tariffs Explained
A variable tariff (sometimes called a standard variable tariff or SVT) means your unit rate can change, typically with 30 days’ notice from your energy supplier. The rate you pay tracks movements in the wholesale energy market, meaning your business energy bill rises when wholesale costs increase and falls when they decrease.
How Variable Energy Pricing Works in Practice
Variable business energy rates are influenced by:
- Wholesale energy market prices — gas and electricity traded on commodity markets
- Global energy supply and demand — geopolitical events, weather, and infrastructure
- The energy price cap — Ofgem, the UK’s energy regulator, sets a cap that limits how much suppliers can charge domestic customers, but business energy contracts don’t fall under the same price cap protection
- Your supplier’s commercial decisions — suppliers set their own variable rates within regulatory guidelines
This matters because business energy contracts don’t benefit from the domestic energy price cap. Variable business tariffs can therefore move more freely than domestic ones, which makes the risk higher for commercial customers.
Advantages of a Variable Business Energy Tariff
Prices could fall in your favour. If wholesale energy costs drop, your rates should follow. In a falling or stable energy market, variable tariffs can end up cheaper over time.
No exit fees. Variable contracts typically allow you to switch suppliers or move to a fixed deal without penalty. This flexibility suits businesses whose energy needs or circumstances change frequently.
No long-term commitment. If energy prices fall sharply or a better energy deal appears, you can act immediately. Your current energy supplier cannot hold you to terms that no longer work for your business.
Disadvantages of a Variable Business Energy Tariff
Unpredictability. Your energy bill can rise with little warning. Budgeting becomes harder when unit rates fluctuate. A price rise of even 2–3p per kWh adds up fast for businesses that use large amounts of energy.
Vulnerability to market shocks. Energy markets can move rapidly. Events like supply disruptions, extreme weather, or geopolitical crises can push wholesale prices and your bill dramatically higher in a short time.
Supplier will automatically roll you onto variable rates. When a fixed contract ends, most suppliers default you onto a standard variable tariff if you don’t actively renew or switch. These rollover rates are often significantly higher than market rates, making inaction expensive.
Fixed vs Variable Business Electricity: Side-by-Side Comparison
| Factor | Fixed Rate Tariff | Variable Tariff |
| Unit Rate | Locked for contract duration | Moves with the market |
| Standing Charge | Usually fixed | Can change |
| Bill Predictability | High | Low |
| Protection from price rises | Yes | No |
| Benefits from price falls | No | Yes |
| Exit Fees | Usually yes | Usually no |
| Contract Length | 1–5 years typical | Rolling/monthly |
| Best for | Stable, predictable businesses | Flexible, lower-usage businesses |
| Risk Level | Low (cost certainty) | Medium to High |
| Price Cap Protection | Not applicable to business | Not applicable to business |
Is Fixed or Variable Better for Business Electricity in 2026?
The honest answer is: it depends on your business, your energy usage, and current market conditions.
In 2026, energy markets remain influenced by global energy supply pressures, the ongoing transition to renewable energy sources, and infrastructure investment costs. Wholesale prices have stabilised compared to the extreme volatility of 2021–2023, but they have not returned to pre-crisis lows.
The case for locking in a fixed rate in 2026: If energy prices remain elevated or show signs of rising, securing a competitive fixed rate tariff now protects your business energy bill for the duration of the contract. With the global energy transition creating structural cost pressures, many energy experts argue that wholesale prices are unlikely to return to historically low levels in the near term.
The case for staying variable in 2026: If you expect wholesale costs to soften, driven by increased renewable energy capacity, reduced gas demand, or new power supply coming online, a variable plan may deliver savings. This view requires confidence in market direction that even professional energy analysts struggle to maintain consistently.
The pragmatic approach for most businesses: Unless you have specific reasons to believe prices will fall, and the financial resilience to absorb higher bills if they rise, a fixed business energy contract typically offers better risk management. The certainty of knowing your energy cost per unit makes it easier to price your products and services, manage cash flow, and plan investment.
How Much Energy Does Your Business Use? Why It Changes the Calculation
The right tariff type is also a function of your energy consumption profile.
High energy users: manufacturers, data centres, hospitality, large retail face significantly more financial exposure on variable tariffs. A 1p per kWh increase on 500,000 kWh annual consumption adds £5,000 to your annual energy bill. For these businesses, fixed rate contracts provide essential cost control.
Low to moderate energy users small offices, service businesses, professional firms, have less financial exposure per unit of energy, so variable tariff risk is more manageable. The flexibility of no exit fees and the ability to switch when better terms emerge can be genuinely advantageous.
Energy usage that is seasonal or highly variable complicates fixed rate analysis. If your business uses power intensively for three months and almost nothing for nine, a fixed daily standing charge can distort your cost per unit of energy consumed significantly.
The key principle: the more energy you use, the more important rate certainty becomes.
What Is a Standard Variable Tariff (SVT) for Business Energy?
A standard variable tariff means your business is placed on a default rate by your current energy supplier; usually because your fixed contract expired without renewal, or because you never negotiated a specific deal. SVTs are typically the most expensive way to buy business energy.
Most businesses end up on SVTs through inaction, not choice. When a fixed deal ends, the supplier will automatically move you onto their standard variable rate unless you actively renew or switch. These rates often carry a significant premium over competitive market rates.
Expert warning: Never allow your business energy contract to lapse onto an SVT without actively reviewing the market. Depending on how much energy you use, the cost difference between an SVT and a negotiated fixed rate tariff can be substantial, often 20–40% more per unit in a normal market.
Fixed vs Variable: What Happens to Your Energy Bill When Prices Change?
Understanding this in concrete terms helps when choosing the right tariff.
Scenario 1: You’re on a fixed rate, and wholesale prices rise 30% Your bill stays the same. Your competitor on a variable plan sees their energy costs spike. You have a competitive cost advantage for the duration of the contract.
Scenario 2: You’re on a fixed rate, and wholesale prices fall 25% Your bill stays the same. Your competitor on a variable tariff benefits from lower rates. You are paying above market rate for the remainder of your fixed contract.
Scenario 3: You’re on a variable tariff, and prices are stable for 18 months. Your rates remain broadly consistent. You avoid the commitment of a fixed deal and retain flexibility. If a better energy deal appears, you can move without exit fees.
Scenario 4: You’re on a variable tariff, and a global energy supply shock hits. Prices could rise sharply and remain high for an extended period. Your bill increases with little warning. You cannot easily move to a fixed rate mid-crisis because suppliers price in the risk, meaning fixed rates available during a price spike may be higher than your current variable rate.
Energy Tariffs Explained: Other Contract Types to Know
Fixed and variable are the two main categories, but business energy contracts come in several variations:
Fixed Price Tariff — the most common fixed option; unit rate and standing charge locked for a set term.
Flexible / Indexed Tariff — unit rates are linked to wholesale market indices and adjusted periodically (daily, monthly, or quarterly). Common for larger energy users who want market exposure but with structured risk management. Not the same as a standard variable tariff.
Dual Fuel Contracts — a single contract covering both electricity and gas from one supplier. Can simplify billing and administration. Dual fuel deals sometimes offer marginal discounts, but not always — compare electricity and gas separately as well as combined to verify.
Deemed Rate Contracts — the rate applied when a business occupies new premises without establishing a formal contract. Often the most expensive rate of all. Always negotiate a contract as soon as you take on new premises.
Half-Hourly Metering Contracts — for larger businesses whose electricity demand exceeds 100kW, half-hourly metering is mandatory. Rates are settled against actual market prices in each half-hour period. These businesses effectively always pay a form of variable rate tied to real-time wholesale costs.
How to Compare Business Energy Suppliers and Find the Best Deal
Making an informed decision on your business energy contract requires more than comparing headline unit rates.
Step 1: Know your current energy usage. Pull your last 12 months of bills. Know your annual kWh consumption for electricity and gas separately. This figure is the foundation of every meaningful price comparison.
Step 2: Understand your contract end date. Find out when your current fixed deal ends. Note any notice periods required. Many business energy contracts require 30–90 days’ notice before expiry. Missing this window can result in automatic rollover to an SVT.
Step 3: Compare unit rates and standing charges together. A supplier with a lower unit rate but a high fixed daily standing charge may cost more in total depending on how much energy you use. Always calculate total annual cost, not just pence per kWh.
Step 4: Check for exit fees before switching. If you’re still within a fixed contract, calculate the exit fee against the potential savings of switching. In many cases, paying to leave early is still financially worthwhile if the new rate is significantly better.
Step 5: Compare business energy suppliers beyond price. Consider the supplier’s customer service reputation, billing accuracy, online account management, and experience with businesses of your size and sector.
Step 6: Consider a dual fuel deal. If you use both electricity and gas, getting quotes for electricity and gas together from a single supplier can sometimes yield better terms, but not always. Compare energy both ways.
Step 7: Use a specialist business energy broker or comparison service. The business energy market is less regulated than domestic and more complex. Brokers with access to competitive business energy deals can often find rates not available direct.
Locking in a Fixed Rate: When Is the Right Time?
Knowing your energy usage is only half the equation. Timing matters when locking in a fixed rate tariff.
Buy when markets are low, not when they are high. This sounds obvious, but many businesses rush to fix rates during periods of market panic, exactly when fixed rates are priced most expensively because suppliers are pricing in elevated risk.
Renew early when rates are favourable. Most suppliers allow you to agree a new fixed contract 6–12 months before your current one expires. If current wholesale rates are lower than your existing rate, locking in early makes sense.
Watch wholesale market signals. You don’t need to be a trader to track broad energy market trends. Ofgem publishes wholesale market commentary. Energy industry publications and your broker can provide context on whether prices could move up or down.
Never fix at the peak of a price spike. If energy markets are in crisis and prices are at historic highs, locking in a long-term fixed rate at that moment crystallises the worst possible price. In extreme market conditions, a shorter fixed term or even a brief period on variable, while waiting for rates to normalise may be preferable.
Renewable Energy Options: Fixed vs Variable on Green Tariffs
Renewable energy sources now underpin a significant proportion of UK electricity generation. Many business energy suppliers offer green or renewable-backed tariffs, and these come in both fixed and variable versions.
A fixed rate renewable tariff means your business can commit to known energy costs while also meeting sustainability and ESG targets. For businesses with net-zero commitments, this combines two objectives efficiently.
Variable renewable tariffs exist but are less common in the business market. The same risk profile applies: costs can move, but you maintain flexibility.
Expert note: “Renewable” labelling on business energy tariffs refers to the energy being matched by Renewable Energy Guarantees of Origin (REGOs) certificates. This does not mean the electricity supplying energy to your premises is physically generated from renewable sources at the point of use. It means the equivalent amount has been generated from renewable energy sources and fed into the grid. Understand the distinction before making environmental claims based on your tariff.
Energy Saving Tips to Reduce Your Business Energy Bill Regardless of Tariff
Whether you’re on a fixed or variable plan, reducing the amount of energy you use is always the most reliable way to cut your energy cost.
Conduct an energy audit. Identify where your business uses the most power. Heating, lighting, and process equipment are typically the largest consumers.
Install LED lighting throughout. Switching from fluorescent or halogen to LED can cut lighting energy use by 60–75% with minimal disruption.
Optimise heating and cooling schedules. Programme HVAC systems to match actual occupancy patterns. Heating an empty building overnight is one of the most common sources of unnecessary energy cost.
Invest in smart metering. Real-time visibility of energy consumption enables faster identification of waste. Many business energy suppliers offer smart meters at no upfront cost.
Consider on-site generation. Solar PV installations have fallen significantly in cost. For businesses with suitable roof space, generating part of your own electricity reduces dependency on the grid and the tariff you pay.
Review refrigeration and compressed air systems. These are often overlooked but can account for 15–30% of energy use in food service, manufacturing, and light industrial businesses.
Reducing how much energy you use has a compounding effect: it lowers your bill on both fixed and variable tariffs, reduces your exposure to price rises, and improves your carbon footprint — all simultaneously.
Frequently Asked Questions
Is fixed or variable better for electricity?
For most businesses, a fixed rate tariff is better for electricity because it provides cost certainty, protects against price rises, and simplifies budgeting. Variable tariffs are only preferable when energy prices are expected to fall significantly, or when business circumstances require maximum contract flexibility. The right choice depends on your energy usage, risk tolerance, and current market conditions.
Is it better to have a fixed or variable tariff?
A fixed tariff is better when energy prices are stable or rising, and when your business needs predictable costs. A variable tariff is better when prices are falling, when you have low energy usage, or when you need the flexibility to switch without exit fees. Most energy experts recommend fixed tariffs as the default for businesses that use significant amounts of energy.
Is it better to be fixed or variable?
Fixed is generally better for businesses that prioritise cost certainty and protection from market volatility. Variable is better for businesses that want flexibility and are willing to accept the risk of price changes in exchange for potentially lower costs when the market moves in their favour. There is no universally correct answer. It depends on the specific business situation.
Is fixed or variable cheaper?
Neither is inherently cheaper. Over time, a fixed rate tariff is cheaper if energy prices rise after you lock in. A variable tariff is cheaper if prices fall below your fixed rate during the same period. Because future energy prices are uncertain, the choice between fixed and variable is a risk management decision as much as a cost decision.
Which is better, fixed or variable?
For the majority of UK businesses in 2026, a fixed rate business energy contract offers better overall value because it eliminates price uncertainty, protects against market volatility, and makes financial planning more straightforward. The exception is businesses with very low energy usage, high need for contract flexibility, or strong conviction that wholesale energy prices will fall during the contract period.
What does 4% variable mean?
A 4% variable rate in a business energy context typically refers to a tariff where the unit rate can vary by up to 4% per billing period, or it may refer to a rate that is set at a fixed margin above a benchmark index. The exact meaning depends on how the specific contract is worded. If your energy contract includes “4% variable” language, ask your supplier to explain precisely what triggers a rate change and by how much your bill could change. Always get this clarified in writing before signing.
