Why did my electricity bill jump?
A bill that suddenly doubles rarely has one single cause — it's usually one of a short list of explanations. This guide walks through ten of them in order of likelihood, with a simple test for each.
Before assuming a fault or overcharge, it helps to work through possible causes systematically — most sudden increases turn out to be explainable by usage or billing mechanics rather than an error. This guide is a diagnostic starting point; for a confirmed dispute, your utility's billing office is the authority that can investigate and correct a bill.
On this page
Ten causes below, ordered roughly by how often they explain a spike, followed by an FAQ.
The ten causes
1. You crossed a slab boundary
How to test: Compare this month's total units to last month's. If you moved from, say, 395 to 410 units, the last 10 units and part of the rest jumped to a higher per-unit rate — and in LT-A, crossing 400 pushes a whole new block to ৳15.01/unit.
2. This month (or last month) was an estimated reading
How to test: Check for the word 'estimated' on the bill. An estimate that undercounted a prior month gets corrected with a catch-up charge later, which can look like a spike even though average usage didn't change.
3. Your AC lost efficiency
How to test: A dirty filter, low refrigerant or a dirty outdoor coil can raise an AC's power draw by 20–40% for the same cooling. If the AC runs longer than usual to reach the same temperature, this is a strong suspect — get the filter cleaned and coils serviced.
4. The meter itself is faulty or running fast
How to test: Turn off every appliance and check whether the meter's indicator (a spinning LED or pulse) is still active. If it's still registering with a true zero load, request a meter test from your utility.
5. Someone is drawing power from your line
How to test: Compare your bill's units to a manual reading you take yourself over a few days when you know your exact usage pattern. A persistent, unexplained gap can indicate an unauthorised tap point on your line — report it to your utility for inspection.
6. Arrears or a surcharge carried over
How to test: Check whether the bill includes a separate arrears or late-fee line rather than a jump in the energy charge itself — this means your actual consumption didn't rise at all.
7. The meter's multiplying factor changed or was misread
How to test: If your connection uses a CT-metered setup, confirm the MF printed on the bill against your previous bill. An MF that changed from, say, 1 to 40 after a meter swap would apply full commercial-scale readings.
8. Genuine seasonal increase
How to test: Compare against the same month last year, not last month. AC-heavy households can see summer bills 2–3x higher than winter ones purely from ambient temperature, with no fault anywhere.
9. A new appliance joined the household
How to test: List anything added in the last billing cycle — a second fridge, an induction cooker, an aquarium pump. Use the appliance cost calculator to estimate its monthly draw and see if it explains the gap.
10. Standby and always-on loads accumulated
How to test: Router, set-top box, old CRT/plasma TV, phone chargers left plugged in, and an IPS trickle-charging 24/7 can together add 30–60 units a month without anyone actively using them. Unplug a batch for a week and watch the daily meter reading change.
Cross-check with the calculators
Once you've narrowed down a likely cause, use the bill calculator to re-price your actual units and confirm the expected total, or the appliance cost calculator to check whether a new or inefficient appliance explains the gap. See also current tariff rates to confirm you're being billed the right category.
Key takeaways
- • Slab crossings and estimated readings explain most unexplained spikes.
- • Compare against the same month last year, not just last month, for seasonal context.
- • A meter test is available on request if you suspect a hardware fault.
- • Standby loads can quietly add 30–60 units a month with nobody actively using power.
- • Bring dated evidence — meter photos, appliance lists — to any formal complaint.
Frequently asked questions
How much of a jump is 'normal' between seasons?
A 30–80% rise from a mild month to peak summer is common for AC-owning households and isn't necessarily a fault. Anything beyond that, or a jump with no seasonal or lifestyle explanation, is worth investigating.
Can I request a formal meter test?
Yes — most utilities offer meter testing on request for a fee (refunded if the meter is found faulty), listed on the tariff/fees schedule. Ask your local billing office how to file the request.
Is an estimated bill legal?
Utilities are generally permitted to estimate a bill when a reading can't be taken, and it's corrected against the actual reading in a later cycle. If you believe an estimate is inaccurate, you can request an immediate re-read.
My bill jumped but I was away all month. What should I check first?
First check for standby loads (fridge, router, aquarium, security lights) and confirm the meter reading wasn't estimated from a higher-usage month. If usage is genuinely near zero and the bill doesn't reflect that, request a re-check.
Should I suspect meter tampering by a neighbour immediately?
It's one of the less common causes and hard to self-diagnose — rule out slab crossing, estimated readings and appliance changes first, since those explain the vast majority of spikes.
Also read how to read your bill and how to cut your bill.