The Complete Guide to Energy Tariffs in the UK

Reviewed by Ed WilkinsonLast updated: July 20, 2026 4:42 pm

Image credit: Mateusz Feliksik @Pexels

What is an Energy Tariff?

An energy tariff is the plan you agree with a supplier that sets out the unit prices and daily standing charges for the gas and/or electricity supplied to a home or business, along with key terms such as contract length and any exit fees. Your choice of tariff directly affects your bills, so understanding how tariffs are structured helps you manage costs.

Understanding the Components of an Energy Tariff

Energy tariffs are composed of several key elements that directly impact the final cost on your energy bill:

• Tariff type and region: Prices depend on the tariff you choose (for example, fixed, variable or time-of-use) and the region you live in, as network and wholesale costs vary by area.
• Standing Charge: A fixed daily fee that helps cover the costs of maintaining the energy networks, metering and supplier operations. It applies regardless of how much energy you use.
• Unit Rate: The price charged per kilowatt-hour (kWh) of energy you use. It does not increase with higher usage within the same tariff; it varies by tariff, meter type (for example, Economy 7), and region.

Factors Influencing Energy Tariffs

Several factors can affect the pricing of energy tariffs:

• Market Conditions: Changes in wholesale energy prices feed through to retail tariffs. On default variable tariffs, adjustments are typically reflected when Ofgem updates the price cap each quarter.
• Regulatory Changes: Government policies, environmental levies and VAT can influence what suppliers charge. Ofgem’s price cap also sets an upper limit on default variable tariff rates.
• Seasonal Demand: Demand and weather patterns can affect wholesale costs and the availability of renewable generation, influencing tariff levels over time.

The Importance of Regular Tariff Reviews

With energy prices subject to change, it’s sensible to review your tariff at least annually, ahead of Ofgem’s quarterly price cap¹ updates (typically January, April, July and October), or whenever your usage or household circumstances change. This helps ensure you are on a cost-effective plan and not overpaying.

By understanding and actively managing your energy tariff, you can make informed decisions that may lead to savings and a lower environmental impact. If you need impartial guidance, consider resources such as Citizens Advice² or the Energy Saving Trust³.

How do Energy Tariffs Work?

Energy tariffs comprise two main charges: a standing charge and a unit rate. The standing charge is a fixed daily cost that applies regardless of how much energy you consume and helps cover the costs of maintaining networks and metering. The unit rate is the price per kilowatt-hour (kWh) of electricity or gas you use. Your total bill will vary according to how much energy you consume.

Additional Charges That May Apply

Aside from the standing charge and unit rate, other fees might be part of your energy tariff:

• Exit Fees: Some fixed-term tariffs include a fee if you switch suppliers before your contract ends. You cannot usually be charged an exit fee within 49 days of the tariff’s end date, and default variable tariffs do not have exit fees.
• Connection Fees: New connections (for example, a newly built property) may incur a one-off charge from your network operator or supplier. Switching supplier for an existing property is normally free and does not interrupt your supply.

Impact of External Factors on Unit Rates

The unit rate is influenced by a variety of external factors, including:

• Changes in wholesale energy prices that reflect global and regional supply-and-demand dynamics.
• Governmental policies, including taxes and levies designed to support decarbonisation and energy security.
• Technological advances that improve generation and flexibility, and the mix of energy sources feeding into the grid.

While the standing charge is fixed within a tariff, the unit rate can differ by tariff and can change on variable or tracker tariffs. With a growing share of renewables and the effect of global events on fuel prices, rates can be volatile. Keeping an eye on these changes can help you understand your bills and identify potential savings.

Choosing the Right Energy Tariff

When selecting a tariff, consider both the standing charge and the unit rate. A lower standing charge can be offset by a higher unit rate (and vice versa). Lower-usage households may prefer a higher standing charge coupled with a lower unit rate, whereas higher-usage households might prefer the reverse. Reviewing your historic usage before choosing can lead to more cost-effective decisions.

Regular reviews of your tariff, ideally annually, help ensure you are on a suitable plan for your current usage and market conditions. This proactive approach is financially prudent and supports more efficient energy use.

What Types of Energy Tariffs are Available?

Understanding the different types of energy tariffs available can help you make an informed decision tailored to your usage patterns and financial goals. Below is a more detailed exploration of each tariff type:

• Fixed tariffs – These tariffs lock in the price you pay for each unit of energy (and the standing charge) for a set period, typically 12-24 months, sometimes up to 36 months. They can aid budgeting and protect against price rises, but if market prices fall, you may pay more than a new deal. Exit fees often apply if you leave early.
• Variable tariffs – Prices can rise or fall in line with the market and are usually the supplier’s default tariff. In Great Britain, these are subject to Ofgem’s price cap, which limits the maximum unit rates and standing charges suppliers can charge on default tariffs.
• Tracker tariffs – Pegged to an energy index or wholesale costs and adjusted (often monthly). They can be cheaper when wholesale prices fall, but you must be comfortable with bills that can change frequently.
• Time-of-use tariffs – Designed to incentivise usage during off-peak hours with cheaper rates at certain times. They usually require a compatible smart or multi-rate meter. Popular examples include Economy 7 and Economy 10⁴, which offer cheaper electricity for seven or ten off-peak hours, respectively.

Each tariff type has pros and cons, and the right choice depends on your consumption habits, financial flexibility and how actively you want to engage with the market. Fixed tariffs may suit those seeking stability, whereas variable or tracker tariffs may appeal if you are willing to accept price risk in exchange for potential dips.

With the increasing integration of renewables and ongoing global market fluctuations, understanding your options is important. Regularly reviewing your usage and tariff alignment can help keep you on a cost-effective plan while supporting sustainable practices.

When considering a new tariff, check for additional charges such as exit fees, and be aware that you can usually switch suppliers free of charge. If you are within 49 days of a fixed tariff’s end date, exit fees should not apply. Make sure you understand all terms before switching.

Should I Fix My Energy Tariff?

Fixing your energy tariff sets your gas and electricity unit rates and standing charges for the contract term. This can support budgeting and protect against price rises. In periods of market volatility, a fixed deal can provide cost certainty.

However, if market rates fall, you may pay more than you would on an available variable rate or a new fixed-rate deal. Whether predictability outweighs potential savings from future price dips depends on your risk tolerance and budget.

Assessing Market Trends

Consider recent price movements and how wholesale costs, supply conditions and policy changes might affect tariffs. Forecasts are uncertain, so avoid relying on them alone; instead, balance the value of certainty against the possibility that prices will ease.

Contract Duration Considerations

Fixed contracts commonly run for 12-24 months. Longer terms can provide extended certainty but reduce flexibility if prices fall or your usage changes. Exit fees may apply if you leave early, though these should not be charged within 49 days of the end date. Review your usage and budget before committing.

In summary, fixing can offer stability and protection against rises, but it requires careful consideration of market conditions and your circumstances. Regularly review your needs and available deals to stay on a tariff that suits you.

Will My Fixed Energy Tariff Increase?

On a genuine fixed-term tariff, your agreed unit rates and standing charges should remain the same for the duration of the contract. Your total bill will still vary with how much energy you use. The main exception is changes to VAT, which suppliers must apply.

Understanding Additional Costs

When you fix your energy tariff, the rate you pay per unit of energy does not change for the duration of the contract. However, the overall cost can still be affected by:

• VAT Changes: The standard VAT rate on domestic energy in Great Britain is 5%⁵ as of 2026. Any change to this rate would affect what you pay, even on a fixed tariff.
• Government Energy Policies: Most fixed-term tariffs do not allow suppliers to vary the agreed rates in response to policy or network cost changes during the term. Always check your terms and conditions for any permitted pass-through clauses.

Monitoring Market and Policy Changes

Stay informed about government announcements on taxation and energy policy, and read supplier communications explaining how these may affect your bills. Understanding the context can help you plan ahead.

Preparing for End of Tariff Periods

As your fixed term nears its end, assess the market to decide whether to fix again or choose a different plan. Consider current conditions and any expected changes to VAT or the wider policy landscape.

Regularly reviewing these elements helps you manage your budget effectively and stay aligned with regulatory developments.

What Happens When My Fixed Energy Tariff Ends?

At the end of a fixed term, you are usually moved to your supplier’s default variable tariff. In Great Britain, this is subject to Ofgem’s price cap, but it may be higher or lower than other deals available at the time. Start reviewing options well before your contract ends to secure a suitable follow-on tariff.

Strategies for Managing the Transition from Fixed to Variable Tariffs

To effectively handle the transition from a fixed energy tariff to a variable rate, consider the following approaches:

• Market Comparison: Use reputable comparison services or the Citizens Advice energy price comparison tool to check offers across suppliers.
• Contract Notifications: Set reminders to review your tariff around 42-49 days before it ends. Suppliers typically notify you in this window, and exit fees should not apply within 49 days of the end date.
• Negotiation: Contact your current provider to see if they can offer an alternative fixed deal or a more competitive tariff than their default variable rate.

Understanding the Impact of Shifting to a Variable Tariff

Variable rates can move with market conditions, so your costs may rise or fall as wholesale prices and network charges change. As the market incorporates more renewables, price volatility can be influenced by weather and global supply dynamics.

Keeping informed about market trends and upcoming regulatory changes helps you manage costs effectively. Monitoring prices and sector news can provide timely insights for tariff decisions.

Preparation for End of Tariff

As you approach the end of your fixed tariff period, assess recent price movements and available deals to decide whether to fix again or switch to a different plan. A proactive approach supports cost control and efficient energy use.

Ultimately, acting early and staying informed can help you avoid paying more than necessary when your fixed deal ends.

Can I Keep My Energy Tariff if I Move House?

When moving house, tariffs are generally linked to the property’s meter. You will usually be placed on a “deemed” tariff with the existing supplier at your new address when you move in. You can then switch to a preferred tariff or ask your current supplier whether your existing tariff can be taken with you; not all tariffs are portable, and terms vary by supplier.

Considerations When Setting Up a New Energy Tariff

Setting up a new energy tariff allows you to tailor your plan to your new home’s needs. Here are some key considerations:

• Energy Efficiency: Assess the property’s energy efficiency. Older or less efficient homes may benefit from lower unit rates even with a higher standing charge, whereas efficient homes with low usage may prefer the opposite.
• Household Size: Match the tariff to typical usage. Larger or high-consumption households may find predictable fixed tariffs easier to budget for.
• Current Market Offers: Research current deals from a range of suppliers and consider eligibility or meter requirements (for example, smart meters for time-of-use tariffs).

Steps to Take When Moving House

Transitioning to a new energy supplier or tariff when you move requires careful planning:

1. Notify Your Current Supplier: Inform your current supplier of your move at least two working days before you leave, providing your move-out date and forwarding details.
2. Take Final and Opening Meter Readings: On the day you move out, take final readings for your old property. Take opening readings at your new home and identify the existing supplier to set up a temporary account so you are not on a higher deemed rate for longer than necessary.
3. Compare Tariffs: Use reputable comparison tools or the Citizens Advice⁶ service to review tariffs available in your new area and choose one that fits your usage.
4. Set Up the New Tariff: Once you have selected a tariff, contact the supplier to set up the service. Read the terms and conditions, including any exit fees and the cooling-off period.

Although moving can be busy, it’s a good opportunity to optimise your energy costs. Reviewing and adjusting your tariff in line with your actual usage and market changes can deliver savings and support more sustainable energy use.

Where To Get Help

Energy tariffs and usage patterns can be complex, and the best option depends on your circumstances. For impartial support with choosing or switching tariffs, contact Citizens Advice or consult resources from Ofgem⁷ and the Energy Saving Trust⁸. They can explain your rights, how the price cap works and what to consider before switching.

If energy costs are affecting your wider budget, free and independent money guidance is available from organisations such as StepChange⁹ and National Debtline¹⁰. The information in this guide is educational and does not constitute personal advice.

This article contains external links for further information on topics. Whilst all attempts are made to verify the trustworthiness of these external sources, we accept no responsibilty for the upkeep or security of these external websites. Some of these links in particular are annotated below:

• ¹ https://www.ofgem.gov.uk/information-consumers/energy-advice-households/energy-price-cap-and-standing-charges-explained
• ² https://www.citizensadvice.org.uk/
• ³ https://energysavingtrust.org.uk/
• ⁴ https://www.smartenergygb.org/using-your-smart-meter/understanding-energy/what-is-economy-7
• ⁵ https://business.totalenergies.uk/help-support/getting-started/do-i-qualify-pay-5-vat-my-energy-if-so-what-do-i-need-do
• ⁶ https://www.citizensadvice.org.uk/
• ⁷ https://www.ofgem.gov.uk/
• ⁸ https://energysavingtrust.org.uk/
• ⁹ https://www.stepchange.org/
• ¹⁰ https://nationaldebtline.org/