How to switch energy supplier and tariff (and save)

Switching energy supplier does not cut off your power, it does not require an engineer visit and in most countries with competitive energy markets it takes only a few minutes to initiate online. What it can do is move you to a cheaper tariff, a greener one, or both.

Why reviewing your tariff is worth doing

In countries with competitive retail energy markets, energy suppliers actively compete for customers. Customers who review their tariff regularly — rather than staying on whatever deal they ended up on — tend to pay less than those who stay put. A customer who has never switched, or who rolled onto a default tariff when a fixed deal ended, is often on one of the less competitive deals available.

Beyond price, tariff choice now has an environmental dimension. The rise of genuinely green tariffs — backed by renewable generation or certificates that track the source of electricity — means it is possible to support cleaner energy through the tariff you choose, in addition to or instead of other changes.

• The energy market is dynamic — a deal that was competitive a year ago may not be now. Reviewing annually is a reasonable habit.
• When a fixed-term deal expires, many customers are automatically moved onto a standard or default tariff, which is typically more expensive. This is a common trigger for a useful review.
• Switching supplier is straightforward in most deregulated markets. The administrative process has improved significantly in many countries and often takes less than a week from signing up with a new supplier to the switch completing.

Understand your usage first

Comparing tariffs accurately requires knowing how much energy you actually use. Without this, any comparison is an estimate at best. Start by understanding your energy bill — it contains the key numbers you need.

• Annual consumption in kWh. Look for your annual electricity usage in kilowatt-hours (kWh) and, if relevant, your gas usage. This figure is usually on your bill or available through your online account. Using your actual annual consumption rather than an average household figure gives a more accurate comparison.
• Current tariff name, unit rate and standing charge. These appear on your bill. The unit rate is what you pay per kWh of energy used. The standing charge (or daily charge) is a fixed cost per day regardless of how much you use. Both matter — a lower unit rate with a high standing charge may or may not be better overall depending on how much energy you use.
• Whether you have a smart meter. Smart meters send readings automatically and can also unlock time-of-use tariffs (see below). Some tariff comparisons differ between smart and non-smart meter customers.
• Your meter type. Economy 7 or other multi-rate meters (which charge different rates at different times) require you to understand your day and night usage separately.

Fixed, variable and time-of-use tariffs

The three main tariff structures differ in how prices are set and how flexible they are.

• Fixed-rate tariffs lock your unit rate and standing charge for a set period — typically 12, 18 or 24 months. Your cost per unit does not change during the fixed term regardless of wholesale price movements. This gives predictability and protection if wholesale prices rise, but means you will not automatically benefit if prices fall. There may be exit fees if you switch before the term ends — check before signing up.
• Variable (or standard) tariffs can change in line with wholesale prices or supplier decisions, subject to any regulatory caps that apply in your country. They are more flexible — usually no exit fees — but less predictable. In some periods they have been cheaper than available fixed deals; in others, significantly more expensive.
• Time-of-use (TOU) tariffs charge different unit rates depending on when you use electricity. Smart meters make these possible by recording usage by time of day. TOU tariffs can offer cheaper electricity during off-peak hours — overnight, for example — which suits people who can shift energy use (charging an EV at night, running the dishwasher on a timer) but may cost more if your usage is mostly in peak hours.

Green and renewable tariffs

Not all tariffs marketed as "green" are equal. Understanding what a green tariff actually means helps you make a more informed choice. See our green energy tariffs guide for a detailed breakdown.

• Renewable Energy Guarantees of Origin (REGOs) or equivalent certificates. In many countries, suppliers can claim their electricity is "green" by purchasing certificates that represent a unit of renewable electricity fed into the grid — without being directly connected to specific generation. This is the most common form of "100% renewable" claim. It is not meaningless — it does channel money towards renewable generation — but it is not the same as having dedicated renewable supply.
• Directly backed by renewable generation. Some suppliers own or contract directly with renewable generators — wind farms, solar parks, hydro schemes — and match their customers' usage against actual output from those sources. This is generally considered a stronger form of green supply.
• Questions to ask. What percentage of supply is from renewable sources? How are the renewables procured — certificates, power purchase agreements or direct ownership? Are there any additional environmental commitments, such as not investing in fossil fuels?
• Gas. Truly renewable gas (biomethane injected into the grid) exists but is a small fraction of supply. "Green gas" tariffs typically involve a proportion of biomethane backed by certificates. The environmental case is weaker than for renewable electricity, but some tariffs do include a proportion of genuinely lower-carbon gas.

How to compare tariffs

The comparison process is straightforward once you have the key information assembled. Energy comparison websites are the most practical tool in markets where they are available — they aggregate current tariff offers and allow you to compare by price for your usage level, tariff type and postcode.

• Use your actual annual consumption figures (kWh of electricity and gas) rather than national averages, which may not reflect your household.
• Compare the estimated annual cost for your consumption level, not just the unit rate in isolation.
• Note the contract length and any exit fees. A deal that is modestly cheaper but has a high exit fee may not be better value if you might want to switch again before it ends.
• Check customer service ratings. A supplier with slightly better prices but consistently poor customer service can create significant frustration when billing errors or supply issues arise.
• If you want a green tariff, look beyond the "100% renewable" label at what it actually means — some comparison sites now filter for specific types of green certification.
• Tariff availability varies by country, region and meter type. Not all tariffs shown on a comparison site may be available to you — the process of getting a formal quote will confirm this.

The switching process

In most deregulated energy markets, the practical process of switching is straightforward. Your power is not interrupted at any point.

1. Gather your information: annual usage in kWh, your current tariff details, postcode, meter number and bank details for direct debit.
2. Use an independent energy comparison site (or visit your preferred supplier's website directly) and enter your usage and location details.
3. Compare the results by total estimated annual cost. Note the tariff type, contract length and exit fee for each option.
4. Read the terms of your chosen tariff, including how long it is fixed for, what the exit fee is (if any) and what happens at the end of the term.
5. Sign up with the new supplier, providing your details. You will usually need to give your current supplier's name and your current meter reading.
6. The new supplier contacts your old supplier and manages the switch. In many countries the switch completes within a few days to a couple of weeks. You should receive a confirmation from both suppliers.
7. Take a meter reading on or around the switch date. This ensures the final bill from your old supplier is based on an accurate reading rather than an estimate.
8. Check the final bill from your old supplier and the first bill from your new supplier. Verify that the meter readings and opening/closing figures match what you recorded.

After switching: meter readings and checks

A small amount of vigilance in the first billing period with your new supplier avoids the most common switching-related problems.

• Submit your own meter reading at the switch date rather than relying entirely on estimated readings. Disputes about the final bill with the old supplier are usually straightforward to resolve with a dated reading.
• Check the first bill from your new supplier shows the unit rate and standing charge you signed up for. Errors happen — it is easier to catch and correct them early.
• If you have credit with your old supplier (you have paid more than you have used), they are usually required to refund it within a defined period. Chase this if it does not arrive.
• If switching did not go as expected — for example, if the switch did not happen, or you received bills from both suppliers simultaneously — contact both suppliers. Most countries have an energy ombudsman or regulator you can escalate to if issues are not resolved.

Using less matters too

Switching tariff is worth doing, but the most reliable way to lower your energy bill and your environmental impact is to use less energy in the first place. Switching supplier changes the rate; reducing consumption changes the volume. The two work together.

See our save energy at home guide for specific actions — many of which cost nothing upfront and have an immediate effect on your bills. The habits and small investments that cut your consumption give you a permanent reduction in what you spend, regardless of what tariff you are on.

• A more efficient home means switching to a cheaper tariff saves more in absolute terms — the same percentage saving applied to a lower baseline.
• A smart meter, which many suppliers offer free of charge during a switch, helps you see your consumption in real time and identify where energy is being used unnecessarily.
• Time-of-use tariffs reward shifting loads to off-peak hours — but only if you can actually change when you use energy. Worth considering if you have an EV to charge or can run appliances overnight.

• Annual electricity and gas usage (kWh) noted from your bill.
• Current unit rate and standing charge identified.
• Any exit fees on your current tariff checked.
• Used a comparison site or direct supplier quotes to compare total annual cost.
• Checked what a "green" tariff claim actually means before choosing one.
• Signed up with new supplier and received confirmation from both old and new.
• Meter reading taken and submitted at the switch date.
• First bill from new supplier checked against expected tariff terms.