Choosing the right business electricity tariff can have a significant impact on your company’s energy costs and financial planning.
For many UK businesses, one of the most important decisions is whether to choose a fixed business electricity tariff or a variable business electricity tariff.
A fixed tariff can provide greater price certainty by locking in the electricity unit rate for an agreed period. A variable tariff, on the other hand, allows the price you pay for electricity to move up or down according to the terms of the contract and underlying energy costs.
Neither option is automatically better for every business. The right choice depends on your electricity consumption, cash flow, tolerance for price changes, contract requirements and expectations about the energy market.
In this guide, we’ll explain how fixed and variable business electricity tariffs work, their advantages and disadvantages, and what businesses should consider before choosing a contract.
Important: Business electricity contracts are commercial agreements, and the exact pricing structure and conditions vary between suppliers. Always check the full terms of a tariff before agreeing to a contract.
What Is a Business Electricity Tariff?
A business electricity tariff is the pricing structure under which a company pays for its electricity supply.
The tariff normally determines how much the business pays for the electricity it consumes and may also specify a standing charge and other contractual costs.
Business electricity tariffs can be structured in different ways. Two of the most important categories are:
- Fixed tariffs
- Variable tariffs
Ofgem explains that businesses can choose different types of energy contracts, including fixed-rate and variable contracts. Under a fixed-rate contract, the price per unit is fixed for the contract period, subject to any conditions in the agreement. Under a variable contract, the amount paid for energy can change during the contract.
This distinction is important because the tariff you choose can affect both your company’s budgeting and exposure to changes in energy prices.
What Is a Fixed Business Electricity Tariff?
A fixed business electricity tariff is a contract where the agreed price per unit of electricity remains fixed for a specified period.
For example, imagine a business agrees to:
- Unit rate: 25p per kWh
- Standing charge: 60p per day
- Contract length: 24 months
If the contract terms specify that the electricity unit rate is fixed, an increase in wholesale energy prices would not normally change that agreed unit rate during the fixed period.
However, businesses should not assume that every component of their commercial energy bill is necessarily fixed.
Some contracts can contain provisions allowing certain charges to change. Ofgem specifically advises businesses to check whether a fixed-rate contract contains conditions that could allow the rate to change.
Always read the contract carefully before signing.
What Is a Variable Business Electricity Tariff?
A variable business electricity tariff allows the price of electricity to change during the contract according to the supplier’s pricing structure and the terms agreed with the business.
If energy costs increase, the price charged to the business may increase.
If energy costs decrease, the price may also fall.
This creates greater exposure to market movements than a genuinely fixed unit-rate contract.
Variable contracts can therefore provide flexibility, but they can also make future electricity costs more difficult to predict.
The exact rules governing price changes depend on the individual contract, so businesses should understand how and when the supplier can change the price.
Fixed vs Variable Business Electricity Tariffs
The fundamental difference is price certainty versus exposure to changing prices.
| Feature | Fixed tariff | Variable tariff |
|---|---|---|
| Unit price | Generally fixed for agreed period | Can change |
| Budgeting | More predictable | Less predictable |
| Exposure to rising prices | Lower during fixed period | Higher |
| Benefit if market prices fall | Limited | Potentially greater |
| Contract flexibility | Often more limited | Can be more flexible |
| Long-term certainty | Higher | Lower |
| Market exposure | Lower | Higher |
| Best suited to | Businesses prioritising certainty | Businesses comfortable with price changes |
These are general characteristics rather than guarantees. The exact terms depend on the supplier and contract.
How Does a Fixed Business Electricity Tariff Work?
Suppose a business signs a 12-month fixed electricity contract at:
24p per kWh
The business uses 30,000 kWh during the year.
Its simplified electricity usage cost would be:
30,000 × £0.24 = £7,200
If wholesale electricity prices rise during the contract, the agreed unit rate may remain 24p per kWh if the contract genuinely fixes that rate.
This gives the business greater certainty when forecasting energy expenditure.
However, if market prices fall significantly, the business generally remains committed to the agreed rate until the contract ends, subject to the terms of its agreement.
This is one of the key trade-offs of a fixed tariff.
How Does a Variable Business Electricity Tariff Work?
Now imagine another business has a variable electricity tariff.
Its initial electricity rate is:
24p per kWh
If market-related costs increase and the supplier changes its tariff according to the contract, the business could end up paying more per kWh.
If the price falls, the business could potentially benefit from lower rates.
For example, if the rate moved from 24p to 28p per kWh and the business used 30,000 kWh:
30,000 × £0.28 = £8,400
That is £1,200 more than the £7,200 usage cost at 24p per kWh.
Conversely, if the rate fell to 21p per kWh:
30,000 × £0.21 = £6,300
The business would save £900 compared with the original 24p rate.
These examples are illustrative only and do not represent current market quotations.
Advantages of a Fixed Business Electricity Tariff
1. Greater Price Certainty
One of the biggest advantages of fixing your electricity rate is predictability.
If your business knows its approximate annual consumption, a fixed unit rate can make it easier to estimate electricity expenditure.
This can be particularly useful for businesses with tight operating margins.
2. Protection From Rising Market Prices
If electricity market prices increase after you agree your contract, your fixed unit rate can protect you from those increases during the fixed period, subject to the contract terms.
This can make budgeting easier during periods of market volatility.
3. Easier Financial Forecasting
A business can use its historical electricity consumption and agreed tariff to build a more predictable energy budget.
For example:
Annual consumption × fixed unit rate + applicable fixed charges
This provides a useful starting point for financial planning.
4. Less Exposure to Market Volatility
Businesses that do not want to monitor wholesale energy markets closely may prefer the relative simplicity of a fixed contract.
Disadvantages of a Fixed Business Electricity Tariff
1. You May Miss Out When Prices Fall
The biggest disadvantage is that price protection works both ways.
If market electricity prices fall after you fix your rate, your business may continue paying the higher agreed rate until the contract ends.
2. Early Exit Can Be Difficult
Many business energy contracts are fixed-term, and suppliers may not allow you to switch before the end of the agreement.
Ofgem states that most suppliers will not allow businesses to switch electricity suppliers before their contract ends.
Some contracts may also include termination or exit charges.
3. Less Flexibility
If your business changes significantly during the contract, the existing tariff may no longer be ideal.
For example, you might:
- Move premises
- Close a location
- Expand operations
- Reduce opening hours
- Install energy-intensive equipment
- Reduce electricity consumption
The contract terms will determine what options are available.
Advantages of a Variable Business Electricity Tariff
1. Potential to Benefit From Falling Prices
If market-related electricity costs fall and your supplier reduces its variable pricing accordingly, your business could benefit.
2. Greater Flexibility
Variable arrangements can sometimes provide greater flexibility than fixed-term contracts, although this depends entirely on the agreement.
Do not assume that every variable tariff can be cancelled or changed without restrictions.
3. Useful During Uncertain Contract Conditions
A business that does not want to commit to a long fixed contract may prefer a variable arrangement while monitoring market conditions.
However, businesses should understand the risks of remaining on variable or default arrangements for extended periods.
Disadvantages of a Variable Business Electricity Tariff
1. Prices Can Rise
The main risk is exposure to increasing electricity costs.
If your business consumes a large amount of electricity, even a small increase in the unit rate can significantly increase annual expenditure.
2. Harder Budgeting
A variable tariff can make it more difficult to predict future energy bills.
Businesses may need to allow additional room in their budgets for potential price increases.
3. Greater Market Exposure
Wholesale electricity costs can be volatile, and business energy prices can reflect a range of costs including wholesale, network and environmental costs. Ofgem reported in March 2026 that wholesale energy costs remained volatile and that business energy prices vary according to factors including the type and size of the business.
Which Is Cheaper: Fixed or Variable Business Electricity?
There is no universal answer.
A fixed tariff could be cheaper if market prices rise after the contract is agreed.
A variable tariff could be cheaper if prices fall.
The problem is that future energy prices cannot be known with certainty.
Therefore, instead of asking:
“Is fixed electricity cheaper than variable?”
businesses should ask:
“Which tariff provides the right balance of cost, certainty and flexibility for my business?”
When comparing offers, consider the expected total cost rather than focusing only on the headline unit rate.
Is a Fixed Business Electricity Tariff Better for Small Businesses?
A fixed tariff can be attractive to a small business energy needs that values predictable costs.
For example, a small retail business may have relatively consistent opening hours and electricity consumption. Knowing the contracted unit rate can make it easier to budget for energy costs.
However, a fixed tariff is not automatically the best option.
Small businesses should also consider:
- Annual electricity consumption
- Contract length
- Standing charge
- Exit fees
- Payment terms
- Renewal terms
- Expected changes to the business
- Ability to absorb price increases
Ofgem’s business energy guidance distinguishes microbusinesses and small businesses and provides specific information about business energy contracts.
Is a Fixed Tariff Better for High-Usage Businesses?
Businesses with high electricity consumption can have significant exposure to changes in unit rates.
For example, a 2p per kWh increase might sound small.
But for a business consuming 500,000 kWh per year:
500,000 × £0.02 = £10,000
A 2p change could therefore represent a £10,000 difference in annual electricity usage costs.
For high-consumption businesses, price certainty can be particularly valuable.
However, the potential benefit must be weighed against the possibility that market prices could fall after the contract is fixed.
What About Standing Charges on Fixed and Variable Tariffs?
The unit rate isn’t the only part of an electricity contract.
You should also examine the standing charge.
A fixed tariff could have:
- Fixed unit rate
- Fixed standing charge
Or the contract could structure some charges differently.
Similarly, a variable contract can have a different standing-charge arrangement.
The exact treatment depends on the supplier and contract terms.
This is why businesses should always compare the complete tariff, rather than assuming that the advertised unit rate tells you the entire cost.
What Other Costs Should Businesses Check?
When comparing fixed and variable electricity tariffs, look beyond the headline price.
Check for:
Unit Rate
How much will you pay per kWh?
Standing Charge
How much will you pay each day?
Contract Length
How long will you be committed?
Exit Fees
Will there be a charge if you leave early?
Pass-Through Charges
Can certain industry or environmental costs change during the contract?
Payment Terms
Will you need to pay by Direct Debit or another method?
Renewal Terms
What happens when the contract ends?
Broker Fees
If you use a broker, find out how they are paid.
Ofgem advises businesses using energy brokers to check their fees, understand which electricity suppliers they work with and review the terms of the broker’s service.
Fixed vs Variable: Which Businesses Might Prefer Each?
There is no universal rule, but the following framework can help.
A Fixed Tariff May Suit Businesses That:
- Want predictable electricity costs
- Have stable electricity consumption
- Prefer financial certainty
- Have limited tolerance for price increases
- Are comfortable committing to a fixed-term contract
A Variable Tariff May Suit Businesses That:
- Are comfortable with changing prices
- Want greater flexibility
- Believe market prices may fall
- Do not want to commit to a longer fixed-term contract
- Can absorb potential increases in energy costs
These are general considerations, not financial advice or a guarantee that a particular tariff will be cheaper.
How to Choose Between Fixed and Variable Electricity Tariffs
Before choosing a tariff, consider these seven questions.
1. How Much Electricity Does Your Business Use?
Look at your historical kWh consumption.
The more electricity you use, the greater the financial impact of changes in your unit rate.
2. How Predictable Is Your Consumption?
If your electricity usage changes significantly from month to month, forecasting your costs may be more difficult.
3. Can Your Business Absorb Higher Energy Costs?
Consider what would happen to your cash flow if electricity prices increased.
4. How Long Are You Willing to Commit?
A longer fixed contract can provide greater price certainty but can also reduce flexibility.
5. What Are the Exit Terms?
Check whether leaving early would result in charges.
6. What Does the Contract Actually Fix?
Do not assume that every charge is fixed simply because the tariff is described as “fixed.”
Read the contract carefully.
7. What Is the Total Estimated Cost?
Compare:
Annual consumption × unit rate + standing charges + other applicable costs
This gives you a better basis for comparing different offers.
What Happens When a Fixed Business Electricity Contract Ends?
When a fixed-term business electricity contract reaches its end date, what happens next depends on the contract terms.
Ofgem explains that businesses can be moved onto different arrangements when a contract ends, including an out-of-contract or deemed contract depending on the circumstances and contract provisions.
Some suppliers may also have rollover provisions.
This makes it important to check your contract well before the end date.
Don’t assume that your current fixed rate will continue indefinitely.
If you’re approaching renewal, compare business electricity options before the existing contract expires.
Can a Business Switch From a Variable to a Fixed Tariff?
Potentially, yes.
A business can explore alternative contracts with its existing supplier or other suppliers, subject to the terms of its current agreement.
If you are considering moving from a variable arrangement to a fixed contract, compare business energy:
- Current unit rate
- New fixed unit rate
- Standing charges
- Contract length
- Exit fees
- Payment terms
- Expected electricity consumption
The goal is not simply to find the lowest headline rate, but to select a contract that fits the business’s financial and operational requirements.
Should You Fix Your Business Electricity Rate Now?
There is no universal answer.
Energy markets change, and the right decision depends on your circumstances.
Ofgem’s current business guidance notes that businesses should consider both short- and long-term contract options and discuss available options with their supplier or broker when a contract is approaching its end.
Before fixing, consider:
- Your current electricity rate
- Historical consumption
- Contract end date
- Cash-flow requirements
- Business growth plans
- Market conditions
- Risk tolerance
- Contract flexibility
If you are unsure, compare commercial energy several offers and carefully review their terms before making a decision.
Common Mistakes When Choosing a Business Electricity Tariff
Choosing the Lowest Unit Rate
A low unit rate doesn’t automatically mean the lowest overall cost.
Ignoring the Standing Charge
A higher standing charge can increase your annual cost.
Fixing for Too Long
A long contract can reduce flexibility if your business circumstances change.
Assuming Everything Is Fixed
Some contracts may allow certain charges to change.
Forgetting the Contract End Date
Leaving the renewal process until the last minute can reduce your options.
Not Checking Broker Fees
If you use an intermediary, understand how they are paid.
Comparing Different Contract Types Without Understanding Them
A fixed tariff and variable tariff carry different risks. Compare business contracts based on their complete contractual terms.
Business Electricity Tariff FAQs
What is a business electricity tariff?
A business electricity tariff is the pricing structure under which a business pays for its electricity supply. It can include a unit rate, standing charge and other applicable costs.
What is a fixed business electricity tariff?
A fixed business electricity tariff generally keeps the agreed electricity unit price fixed for a specified contract period, subject to the terms and conditions of the agreement.
What is a variable business electricity tariff?
A variable business electricity tariff allows the price charged for electricity to change during the contract according to the supplier’s pricing structure and contractual terms.
Is fixed or variable electricity cheaper for businesses?
Neither is always cheaper. A fixed tariff can provide protection against rising prices, while a variable tariff can allow businesses to benefit if prices fall.
Is fixed electricity better for a small business?
A fixed tariff may suit a small business that values predictable costs, but the decision should also consider consumption, contract length, electricity standing charges, exit fees and future business plans.
Can business electricity prices change on a fixed tariff?
The agreed unit rate may remain fixed, but businesses should check the contract because some agreements contain provisions allowing certain charges to change.
Can I switch from a variable to a fixed business electricity tariff?
You may be able to switch, depending on your current contract and supplier terms. Compare the complete cost and contractual conditions before changing.
Does the Ofgem price cap apply to business electricity tariffs?
No. Ofgem states that businesses with non-domestic energy contracts are not protected by the domestic energy price cap.
Final Thoughts
Choosing between a fixed and variable business electricity tariff is ultimately a decision about risk, certainty and flexibility.
A fixed tariff can make electricity costs easier to forecast and can protect a business from increases in the agreed unit rate during the fixed period. However, it can also mean missing out if market prices fall and may involve a longer contractual commitment.
A variable tariff gives businesses more exposure to changing energy prices. That can work in their favour when prices fall, but it can also increase costs when market prices rise.
There is no universally best business electricity tariff.
The right choice depends on your business’s electricity consumption, financial position, tolerance for price changes, contract requirements and future plans.
Before choosing a tariff, compare the unit rate, standing charge, contract length, exit fees and other applicable charges. Most importantly, read the contract carefully so you understand exactly what is fixed and what can change.
If your current business electricity contract is approaching its end, this is a good time to review your options rather than automatically accepting the next available tariff.
Find the Right Business Electricity Tariff
Fixed and variable tariffs can suit different types of businesses. Compare your current electricity deal with available business electricity options and see which type of tariff could work best for your business.