How to Choose Your Energy Supplier in the UK: Save Hundreds a Year by Switching Smartly
If you’re living in the UK, chances are you’ve been shocked by your energy bills.
Even when you barely turn on the heating, the monthly total still feels unreasonably high.
What many people don’t realise is that you can freely choose your energy supplier in the UK.
The price difference between companies for the same usage can be significant — sometimes hundreds of pounds a year.
Here’s a practical guide to help you understand how to choose or switch your electricity, gas, and water suppliers to save money and avoid unnecessary hassle.
1. Electricity and Gas — Always Compare, Because Prices Vary Widely
The UK’s electricity and gas markets are open, meaning you can switch suppliers at any time.
For example, many residents have found that Octopus Energy often offers cheaper and fairer tariffs than traditional companies like British Gas.
Recommended Comparison Websites
You don’t need to check every company manually.
These comparison platforms can show you the best deals in your postcode instantly:
How it works:
Enter your postcode.
Choose whether you want to compare electricity, gas, or dual fuel.
The system will automatically show all available tariffs in your area.
If you find a cheaper supplier, you can click “Switch Supplier” directly online.
Things to Know Before You Switch
New-build apartments or central-heating systems:
Some developments have long-term contracts with specific energy providers.
Short-term tenants may not be able to switch — always confirm with your landlord or agent first.Fixed vs. Variable tariffs:
Fixed rates offer price stability; variable rates fluctuate with the market.Bill structure:
Unit Rate: you pay based on your actual usage.
Standing Charge: a daily fixed fee, charged even if no energy is used.
2. Water Supply — You Can’t Switch, but You Should Know Who Supplies You
Unlike electricity and gas, water suppliers in the UK are region-based and cannot be changed.
However, it’s essential to know which company serves your area and to register an account promptly.
How to Check Your Water Company
Visit Water UK,
enter your postcode, and you’ll see your local supplier.
In London, most households are served by Thames Water.
You can register directly on their website, link your address, and set up automatic payments for convenience.
Major Water Suppliers in the UK
Thames Water (London)
Affinity Water
Scottish Water
South West Water
Sutton and East Surrey Water
3. Central Heating Systems (Heat Networks)
Many new apartment buildings now use heat networks — centralised systems that provide heating and hot water to multiple flats.
In these cases, the developer or management company signs the contract with a heating supplier, and tenants cannot switch.
Before moving in, check with your agent or landlord:
Whether you need to register a separate Heat Network account.
Whether heating and hot water are included in your rent or service charge.
Whether previous tenants have cleared their bills.
Failing to confirm these details can lead to unexpected back payments later.
4. Moving In or Out — Always Record Your Meter Readings
Whether you’re moving into a new flat or preparing to leave, always take photos of your meter readings:
On the move-in day, record your electricity, gas, and water meter readings.
Do it again before moving out — photo or video evidence works best.
Request a Final Bill from each supplier and keep your payment proof (Final Bill Payment Proof).
These records are essential when reclaiming your deposit from landlords or agencies.
5. Quick Summary: How to Save on Energy Bills
Regularly check comparison websites for new tariffs.
Don’t hesitate to switch suppliers — it’s easier than you think.
Keep photo records of all meter readings and bills.
Check carefully if your building uses a central heating or fixed contract system.
With just a bit of attention and initiative, you can save hundreds of pounds each year.
In times of rising energy costs, learning how to manage your suppliers is one of the smartest financial habits to build while living in the UK.