Which is better: fixed or variable energy tariffs?

It depends on your priorities. Choose a fixed tariff if you value price certainty and want to budget confidently. Choose a variable tariff if you want flexibility and are comfortable with prices changing. Comparing the total expected cost (unit rate + standing charge) for your typical usage is the best way to decide.

Can my bill still change on a fixed tariff?

Yes. Even with fixed unit rates, your bill can change if you use more or less energy, if your Direct Debit is adjusted to match usage, or if you have changes to your account (for example, moving home). The key difference is that the price per kWh is fixed for the agreed term.

Do fixed tariffs have exit fees?

Many fixed tariffs include an exit fee if you leave before the end of the term, but this varies by tariff. Always check the tariff details before switching. Some fixed deals may offer no exit fee or allow a fee-free switch close to the end date.

Is a variable tariff the same as a standard variable tariff (SVT)?

A standard variable tariff (SVT) is a type of variable tariff, often the default tariff if you haven’t chosen a fixed deal. SVT prices can change and may be influenced by the energy price cap. Other variable tariffs may have different pricing structures, so it’s worth comparing rates and terms.

When should I consider switching between fixed and variable tariffs?

Consider switching if your current deal is ending, if market prices have moved significantly, or if your budgeting needs have changed. Before switching, compare the new tariff’s unit rate, standing charge, term length, and any exit fees.

How do I choose the right tariff for my home?

Start with your annual usage (kWh) from recent bills or your smart meter. Then compare tariffs by looking at unit rates, standing charges, contract length, and any exit fees. If you want help reviewing options, you can explore plans and guidance on Energy Plus to find a tariff that fits your usage and preferences.

Fixed vs Variable Energy Tariffs (UK): Which Is Best?

Q: What is a fixed energy tariff?

A fixed energy tariff locks in your unit rate (and usually the standing charge) for a set term (for example 12 or 24 months). Your monthly bill can still change if your energy use changes, but the price you pay per kWh stays the same during the fixed period. Fixed tariffs can suit you if you want predictable pricing and protection from market price rises.

Q: What is a variable energy tariff?

A variable energy tariff has rates that can go up or down. Prices may change with the supplier’s costs, wholesale market movements, or when the energy price cap is updated (where applicable). Variable tariffs can suit you if you prefer flexibility and want the option to benefit if prices fall.

Compare fixed and variable energy tariffs for your home, understand the trade-offs, and switch with confidence. EnergyPlus.co.uk is whole-of-market, so you can see options across UK suppliers in one place.

See whether a fixed deal can protect your unit rates for a set term
Understand how variable tariffs track the market and the Ofgem price cap
Check exit fees, contract length, and what happens when your deal ends
Get matched to home energy tariffs based on your postcode and usage

Compare fixed & variable deals Read the quick guide

Home energy only. Switching won’t interrupt your supply. Your tariff choices depend on availability, meter type and location.

Compare fixed vs variable tariffs in minutes

If you’re deciding between a fixed energy tariff and a variable energy tariff, the “best” option usually comes down to how you feel about price certainty, flexibility, and what’s happening in the wider UK energy market. Use the form to see available home energy deals for your postcode.

Tip: Have your latest bill or online account handy. If you know your annual usage (kWh) for electricity and gas, you’ll get a more accurate comparison.

What you’ll see when you compare

Estimated monthly/annual cost based on your usage
Unit rates (p/kWh) and standing charges (p/day)
Tariff type (fixed or variable), term length, and exit fees (if any)
Whether the deal is suitable for your meter and payment method

Why tariff type matters for UK household bills

Predictability vs flexibility

Fixed tariffs can offer steadier unit rates for a term. Variable tariffs typically change with market movements and/or supplier pricing.

What you pay is more than the headline

Your total cost depends on unit rates, standing charges, and your usage (kWh). A “cheaper” tariff can be beaten by a different standing charge.

Deal end dates can quietly cost you

When a fixed deal ends you may roll onto a standard variable tariff. Knowing your end date helps you switch at the right time.

Fixed vs variable: the quick UK guide

In the UK, most households choose between fixed tariffs (your unit rate is locked for a term) and variable tariffs (your unit rate can change). Both have pros and cons, and the right choice depends on your budget, risk tolerance and how long you want to commit.

What is a fixed energy tariff?

A fixed tariff keeps your unit rate (p/kWh) the same for a set period (commonly 12–24 months). Your bill can still change if your usage changes, but the price per unit stays fixed for the term.

Best for: budgeting and avoiding surprises
Watch for: exit fees, longer terms, and what you’ll pay when it ends
Good to know: standing charges may also be fixed, depending on the tariff

What is a variable energy tariff?

A variable tariff can change over time. Many households end up on a supplier’s standard variable tariff (SVT), which can go up or down when prices change (and is generally influenced by the Ofgem price cap level).

Best for: flexibility and switching at any time (usually no exit fees)
Watch for: price rises that increase your monthly costs
Good to know: “price cap” isn’t a cap on your total bill—it’s a cap on unit rates/standing charges for a typical customer profile

Key differences: fixed vs variable tariffs

Use this table to compare what typically changes (and what doesn’t). Individual suppliers vary, so always check the tariff details before you switch.

Feature	Fixed tariff	Variable tariff
Unit rate (p/kWh)	Typically locked for the term	Can change (up or down)
Standing charge (p/day)	Often fixed, but check tariff details	Can change
Contract length	Usually 12–24 months (can vary)	Ongoing / no fixed end date
Exit fees	Common (especially during the term)	Often none (especially SVTs)
Protection from price rises	Yes, for the fixed term (for unit rates)	No—prices can rise
Ability to benefit from falls	Not automatically; you may need to switch (watch exit fees)	More likely to benefit if rates drop

Reminder: Even on a fixed tariff, your bill can change as your usage changes (season, home working, insulation, boiler efficiency). Fixing affects the price per unit, not how many units you use.

Which tariff should you choose?

Use these practical scenarios to decide. If you’re unsure, comparing deals for your postcode is the quickest way to see what’s available right now.

Choose a fixed tariff if…

You want predictable unit rates for a set period
You’d rather avoid the risk of variable prices rising
You’re happy to commit for 12+ months (or the term offered)
You can budget better with steady costs, even if prices later fall

Choose a variable tariff if…

You prefer flexibility and usually want to switch without exit fees
You’re comfortable with price changes (up or down)
You think prices may fall and want to track them more closely
You need a short-term option while you look for a better fixed deal

A simple rule of thumb

If a fixed deal’s unit rates are close to (or lower than) available variable options and you value certainty, a fixed tariff may suit you. If you need flexibility and plan to switch quickly when the market moves, variable may fit better.

Compare tariff types for my postcode Read FAQs

What else affects your home energy costs?

Meter type & payment method

Some tariffs are only available for certain setups (e.g., direct debit, smart meter, or prepayment). If you’re on a prepayment meter, checking eligibility upfront can save time.

Where you live in the UK

Electricity standing charges and unit rates can vary by region due to network costs. That’s why comparing by postcode is important.

Dual fuel vs single fuel

Some suppliers price dual fuel competitively, others don’t. If you have electricity only (for example, no mains gas), it’s worth checking electricity-only deals too.

Your usage (kWh)

High-usage homes can benefit more from a lower unit rate; low-usage homes can be more sensitive to a higher standing charge. Comparing with accurate kWh figures helps.

Common mistakes when choosing a tariff (and how to avoid them)

1) Comparing only the monthly Direct Debit

Monthly payments can be adjusted by suppliers. Always compare unit rates, standing charges, and estimated annual cost.

2) Missing exit fees on fixed deals

If you switch early, exit fees can reduce or erase savings. Check fees before committing—especially with longer terms.

3) Forgetting the deal end date

Set a reminder a few weeks before your fixed tariff ends. It’s often the best time to compare again and avoid rolling onto a higher variable rate.

Fixed vs variable tariffs: FAQs

Is a fixed tariff always cheaper than variable?

Not always. A fixed tariff can be cheaper, similar, or more expensive depending on market conditions and supplier pricing. Fixed deals trade flexibility for certainty. Comparing by postcode is the best way to see current pricing.

Will switching energy supplier cut off my gas or electricity?

No. In normal circumstances your supply continues as usual. The change is administrative—your new supplier takes over the billing.

What’s the difference between variable and standard variable (SVT)?

“Variable” means the price can change. A standard variable tariff is the default variable tariff many households are moved onto when a fixed deal ends, or when you join a supplier without choosing a fixed term.

Does the Ofgem price cap mean my bill is capped?

Not exactly. The price cap is set as a limit on unit rates and standing charges for typical customers on default tariffs. Your total bill still depends on how much energy you use.

When should I switch if I’m on a fixed tariff?

Many suppliers allow switching near the end of your fixed term without paying exit fees. If you’re mid-contract, check for exit fees first. If you’re on SVT, you can usually switch at any time.

What information do I need to compare energy tariffs?

Your postcode, fuel type (gas/electricity), meter type, payment method, and ideally annual usage in kWh from your bill. If you don’t have kWh, you can still start with postcode and update later.

Want to go straight to offers? Compare fixed and variable tariffs for your postcode.

Why households use EnergyPlus.co.uk

Whole-of-market comparison

See a broad range of UK home energy tariffs in one journey, without relying on a single supplier.

Clear tariff details

We focus on the numbers that matter: unit rates, standing charges, term length and exit fees.

Built for real-life switching

Whether you’re on SVT or coming to the end of a fix, we help you compare options that fit your home setup.

Trust note: Always check tariff terms before you commit. If you have a smart meter, Economy 7, or prepayment meter, availability can differ by supplier and region.

Ready to choose between fixed and variable?

Get home energy quotes tailored to your postcode and compare fixed vs variable tariffs side-by-side.

Whole-of-market comparison
Fast form—no complex setup needed
Clear rates, standing charges and contract terms

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You won’t lose supply when you switch. Home energy only.

Quick checklist before you switch

Check your current tariff end date
Look for exit fees (if fixed)
Have your postcode and bill to hand
Compare total estimated annual cost

Back to Energy Comparison

Updated on 3 Feb 2026