Should I fix my energy again or move to a variable rate?

It depends on the deal and your appetite for risk. A new fix gives price certainty and protects you if rates rise, but may carry exit fees and could look dear if the market falls. Staying variable keeps you flexible and benefits if the cap drops, but is the rate most likely to be quietly expensive. If a fix is meaningfully cheaper than your variable rate and you value predictable bills, fixing is often worth it.

Does the standing charge change when my fixed deal ends?

It can. The standing charge is the fixed daily amount you pay to be connected, and it applies on both fixed and variable tariffs. When you roll onto a variable rate or compare a new deal, check the standing charge as well as the unit rate, because a low unit rate can be offset by a higher daily charge.

Can my supplier bill me for energy from years ago after my deal ends?

No, not if the supplier was at fault for failing to bill you correctly. Under back-billing rules, a supplier cannot charge you for energy used more than 12 months ago in those circumstances. Giving regular meter readings and checking your account still helps you avoid surprises.

What happens when your fixed energy deal ends?

Q: What happens if I do nothing when my fixed energy deal ends?

Your supply continues and you are moved automatically onto your supplier's standard variable tariff. That rate is capped by the regulator but usually costs more than a competitive fixed deal. You are not tied in, so you can switch away at any time with no exit fee, but you are likely to be overpaying until you do.

Q: Can I be charged an exit fee at the end of a fixed tariff?

No. In the final weeks before a fixed deal ends, your supplier cannot charge an exit fee for leaving, even if the deal carried exit fees earlier in its term. That gives you a window to compare and switch penalty-free before the end date.

A fixed energy deal has an end date, and that date is one of the few moments when your bill can move sharply without you doing anything at all. The rate you agreed to stops applying, and unless you have chosen something new, you are moved onto a different tariff automatically. Sometimes that costs you more, occasionally less, but it is rarely something to let happen by accident. This guide sets out exactly what happens when a fix ends, the protections you have, and how to decide your next move without panicking.

The short answer. When your fixed tariff ends, you roll onto your supplier's standard variable tariff unless you pick another deal first. The variable rate is capped by the regulator but usually costs more than a competitive fix. In the final weeks before your deal ends you can switch away with no exit fee, which is the window to shop around. Doing nothing is not a disaster, but it usually means paying more than you need to.

What a fixed deal actually fixes

It helps to be clear about what was fixed in the first place, because it is not your bill. A fixed tariff locks the unit rate you pay per kWh of gas and electricity, and the daily standing charge, for the length of the deal, commonly a year or two. It does not fix how much you spend. If you use more energy in a cold winter, you pay more; the price per unit is what stays put.

That distinction matters at the end of the deal, because what changes is precisely those locked numbers. On the end date, the protected unit rates and standing charge fall away, and you move to whatever tariff you are rolled onto next. Your usage habits carry on exactly as before, so any change in the bill comes purely from the new prices.

Where you land by default: the standard variable tariff

If you do nothing, you are not cut off and your supply does not stop. You are simply moved onto your supplier's standard variable tariff, sometimes called the default tariff. This is the ongoing rate that customers sit on when they are not on a fixed deal, and its price can move up or down over time rather than being held steady.

In Great Britain the standard variable rate is limited by the regulator's price cap, which sets a maximum for the average unit rates and standing charges a supplier can charge on it. The cap is a ceiling, not a target, and it is reviewed regularly, so the variable rate is not a fixed shelter; it is a rate that follows the wider market within that limit. A competitive fixed deal often sits below the variable rate, which is why rolling onto the default so often means paying more than you have to. Our guide to how the energy price cap works explains the ceiling in detail.

The final weeks: your free switching window

The single most useful thing to know is that you are not trapped as your deal winds down. In the last stretch before a fixed tariff ends, your supplier cannot charge you an exit fee for leaving, even if the deal carried exit fees earlier in its term. That gives you a window of several weeks to compare tariffs and move, whether to a new deal with your current supplier or to a different one, without any penalty.

Your supplier is required to write to you before the end date to tell you the deal is finishing and what will happen next, including the rate you will roll onto. Treat that letter or email as a prompt to act rather than a formality to file away. This is the natural point to shop around, and our guide to switching suppliers walks through comparing deals and making the move.

Fix again or ride the variable rate?

Once you are in that window, the real decision is whether to lock in another fixed deal or stay on the variable rate for a while. Neither is automatically right, because it is a judgement about where prices go next, and nobody knows that for certain.

A new fix buys certainty. You know your unit rates for the term, which makes budgeting easier and protects you if wholesale prices climb. The trade-off is that you might lock in just before the market falls, and you may face exit fees if you want to leave early. Staying on the variable rate keeps you flexible and lets you benefit if the cap drops, but it exposes you if prices rise, and it is the rate most likely to be quietly expensive over time. As a rough rule, if you can find a fixed deal meaningfully below your current variable rate and you value predictable bills, fixing is often worth it; if the gap is small, flexibility may be worth keeping. Our guide comparing switching options can help you weigh a specific offer.

A worked example

Suppose your fixed deal charged an example 24p per kWh for electricity, and the variable tariff you would roll onto charges 26p. On a fairly typical 2,700 kWh a year of electricity, that 2p difference is about £54 more a year on electricity alone, before you add any change on gas or the standing charge. If a fresh fixed deal is on offer at 23p, moving to it instead of drifting onto the variable rate could be worth close to £80 a year against that variable option.

Illustrative figures only. Real rates vary by region, supplier, meter type and payment method, and change often. Always compare against your own recent usage in kWh, which you will find on a bill or your online account.

Do not forget the standing charge

It is easy to focus only on the unit rate and overlook the standing charge, the fixed daily amount you pay just for being connected, regardless of how much energy you use. It applies on both fixed and variable tariffs, and it does not vanish when your deal ends. When you compare a rollover against a new deal, compare the standing charges as well as the unit rates, because a headline unit rate can be undercut by a higher daily charge, particularly if you are a low user. Our guide to standing charges explained covers why they exist and how much they add.

If you let it roll: what to watch

Letting your deal roll onto the variable rate is not a crisis. Your supply continues, the rate is capped, and you can still switch away at any time with no exit fee because you are no longer on a fixed contract. The risk is simply cost: the variable rate is the one you are most likely to be overpaying on without noticing.

Two habits protect you if you do roll over. Keep giving regular meter readings, or let a smart meter send them, so your bills reflect real use rather than estimates. And remember the back-billing rule: if your supplier is at fault for not billing you correctly, it cannot charge you for energy used more than 12 months ago. That is a backstop against a nasty catch-up bill, not a reason to ignore your account. Check in every few months, and treat any renewal or price-change letter as your cue to compare again.

The bottom line

When a fixed deal ends you roll onto a capped but usually pricier variable rate unless you choose something else, and the weeks before the end date are your penalty-free chance to shop around. Read the letter your supplier sends, note the date, compare unit rates and standing charges against your own usage, and decide calmly whether to fix again or stay flexible. The one thing worth avoiding is doing nothing for months and only later noticing the bill crept up.