A standard variable tariff, often shortened to SVT, is a supplier’s default energy tariff. The price can move up or down rather than being fixed for a set contract period.
Citizens Advice describes a standard variable tariff as a default tariff and says its price usually changes every three months, with reviews in January, April, July and October.
How a standard variable tariff works
On a standard variable tariff, your supplier can change the unit rate and standing charge. If the cost of energy changes or the Ofgem cap changes, your tariff may change too.
Your bill still depends on how much gas and electricity you use. A price change affects the rate charged, but your total cost is also driven by your kWh usage.
energy cost = kWh used × variable unit rate
+ daily standing charge × days
Standard variable tariffs and the price cap
The energy price cap protects households on standard variable and default tariffs by limiting what suppliers can charge for each unit of energy and the daily standing charge.
Ofgem says the price cap protects people on tariffs where the unit rate can go up or down depending on the energy market. These are called standard variable tariffs.
£1,862/year
Typical Direct Debit dual-fuel household for 1 July to 30 September 2026.
Every 3 months
Price-cap periods usually start in January, April, July and October.
Standard variable tariff vs fixed tariff
A fixed energy tariff normally locks agreed rates for a set period. A standard variable tariff can change.
| Feature | Standard variable tariff | Fixed tariff |
|---|---|---|
| Rate certainty | Rates can change. | Rates usually stay fixed for the contract period. |
| Price-cap link | Usually affected by the Ofgem price cap. | Usually has agreed contract rates. |
| Flexibility | Often easier to leave. | May include exit fees. |
| Main risk | Rates can rise. | You may miss out if variable rates fall. |
When might you be on a standard variable tariff?
You may be on a standard variable tariff if you have never switched, if your fixed tariff ended and you did not choose a new deal, or if you moved into a home and stayed on the supplier’s default tariff.
Citizens Advice says if your fixed tariff is coming to an end, you can move onto your supplier’s default tariff, and your supplier will automatically move you onto this tariff when the fixed deal ends.
Pros and cons of a standard variable tariff
| Potential benefit | Potential drawback |
|---|---|
| Often more flexible than a fixed contract. | Rates can rise when the cap rises. |
| You may benefit if variable prices fall. | Harder to budget because prices can change. |
| Protected by the energy price cap if it is a default tariff. | May not be the cheapest available deal. |
What to check before staying on one
A standard variable tariff is not always wrong, but you should compare it with available fixed deals and your own usage.
- Check your current unit rates and standing charges.
- Compare your annual kWh usage, not just monthly payments.
- Look at fixed tariff offers and any exit fees.
- Check when the next price-cap change is due.
- Estimate your annual bill under both options.
Compare your annual cost
Use your own usage, unit rates and standing charges before choosing a tariff.
FAQs
What is a standard variable tariff?
A standard variable tariff is an energy supplier’s default tariff where rates can go up or down.
Is a standard variable tariff protected by the price cap?
Yes, if it is a default domestic tariff, the Ofgem price cap limits unit rates and standing charges.
Is a standard variable tariff cheaper than a fixed tariff?
Not always. It depends on current rates, expected price changes, usage and any fixed-tariff exit fees.
What happens when a fixed tariff ends?
If you do not choose a new tariff, you are usually moved to the supplier’s default standard variable tariff.