Why is my electricity bill higher than last month?
Month-on-month jumps usually come from more usage, more billed days, a catch-up after estimates or a tariff change. The fix is to compare the kWh, reading type and days billed before you compare the pound total.
The month-on-month method
- Put the two bills side by side.
- Compare kWh, billed days and reading type.
- Then compare the tariff rates and standing-charge subtotal.
This is the fastest way to see whether the change is coming from usage, timing or pricing.
Related guides
When the latest bill is the one that matters less
If the previous statement was estimated or unusually short, the latest “higher” bill may actually be the more accurate one. That is why month-on-month comparison needs context, not just instinct.
Official and reference sources
Frequently asked questions
Can a longer bill period alone make the bill higher than last month?
Yes. More billed days can increase the total even if your daily pattern barely changed.
What should I compare first?
kWh, days billed and reading type.
Does a higher direct debit mean the latest bill was higher too?
Not necessarily. They are linked but not the same thing.
The cost-per-day comparison that makes bills comparable
Billing periods are rarely the same length, which makes raw totals misleading. Convert everything to a daily figure and the comparison becomes honest.
| Last bill | This bill | Change | |
|---|---|---|---|
| Total | £184 | £268 | +46% — alarming |
| Days covered | 61 | 92 | +51% |
| Cost per day | £3.02 | £2.91 | −3.6% — it went down |
| kWh used | 612 | 905 | +48% |
| kWh per day | 10.0 | 9.8 | −2% |
Same household, same behaviour, a bill that looks 46% worse. The only thing that changed was the length of the billing period. Before you write anything, do this table for your last four bills — it resolves a large share of high-bill worries in five minutes, and where it does not resolve it, you now have a genuine, quantified anomaly to put in the complaint.
The diagnosis order that saves the most time
Work down this list. Each check is faster than the one below it, and each one rules out a cause that is more likely than the next. Most people start at step 7 and never do steps 1 to 3.
| # | Check | Time | If this is it |
|---|---|---|---|
| 1 | Is the reading estimated? Look for an E beside the readings. | 30 seconds | Submit an actual reading and ask for a rebill. More |
| 2 | How many days does the bill cover? A 3-month bill next to a 2-month bill is not a like-for-like comparison. | 30 seconds | Nothing is wrong. Compare cost per day instead. |
| 3 | Did the rates change? The cap moves every quarter. | 1 minute | Compare kWh, not pounds. That separates price from usage. |
| 4 | Do the readings on the bill match your meter? | 3 minutes | Wrong reading. More |
| 5 | Is the standing charge line right? Days × p/day ÷ 100. | 1 minute | Check for overlapping billed days. More |
| 6 | Has anything changed at home? Occupancy, an EV, electric hot water, a dehumidifier, a colder winter. | 2 minutes | Real usage. Not a billing error. |
| 7 | Does the meter advance with everything off? | 15 minutes | Now you have a meter or crossed-meter case. More |
The single most useful habit: compare kWh, not pounds. A bill that rose 40% in money might be 5% more energy at 33% higher rates. Pounds mix the two together and tell you nothing about which one to complain about. Every bill shows the units used — use those.
What a normal month-to-month change looks like
Before treating a rise as a problem, check whether it is just the calendar. Electricity swings roughly 50% across the year for a typical household; gas swings by a factor of five.
| Comparison | Expected change | Worth investigating if |
|---|---|---|
| October vs September | +15% electricity, +100% gas | Gas has not moved at all — is the heating billing correctly? |
| January vs December | +5% electricity, +5% gas | Either has jumped more than 25% |
| April vs March | −10% electricity, −30% gas | Nothing has fallen — is something still running? |
| July vs June | Roughly flat | Any significant rise. Summer is the month where an anomaly is clearest. |
A high summer bill is the most diagnostic thing on this page. With heating off, usage should be at its floor. A gas bill that stays high in July points at hot water, a heating system running when it should not be, or a reading problem — and it is much easier to isolate in July than in January.
When the supplier is probably right
Worth saying plainly, because a complaint built on a legitimate increase burns credibility you may need later.
The bill follows a long run of estimates
The money was always owed; it was just invisible. Your leverage is the repayment period and the rate apportionment, not whether you owe it. Catch-up bills
Something material changed at home
A new occupant, an EV, an immersion heater, working from home, a baby. These are hundreds of kWh, not tens.
It was a cold quarter
A colder-than-average winter adds 5–15% to gas usage for identical behaviour.
The rates went up
The cap changes quarterly. Compare kWh with the same period last year and the picture is usually clear.
But still ask for this
Even on a legitimate bill: an interest-free repayment period at least as long as the arrears took to build, and confirmation the direct debit was recalculated on your corrected annual forecast rather than forecast plus accelerated recovery.
Frequently asked questions
Why is my bill higher than last month?
Check the number of days each bill covers first. Quarterly and monthly bills are often not the same length, and a longer period makes a bill look worse without anything changing. Convert both to cost per day and kWh per day before drawing any conclusion.
How much should my bill vary month to month?
Electricity varies about 50% between summer and winter for a typical home. Gas varies by a factor of five, because it is mostly heating. A January gas bill four or five times the July one is entirely normal.
My summer bill is high. Is that a bigger warning sign?
Yes. With heating off, usage should be at its annual floor, so a high July bill is the clearest signal there is that something is wrong — hot water, a heating system running when it should not be, or a reading problem.