Understanding your electricity bill

An Irish electricity bill looks more complicated than it is. Underneath the branding, every supplier is billing you for the same four things in the same order, and once you can name them you can compare any two suppliers honestly — and spot the month where something has gone wrong.

The four components

1. Unit charges. Your consumption in kilowatt hours, multiplied by a rate in cents per kWh. On a standard 24-hour meter there is one rate and one line. On a day/night (NightSaver) meter there are two, because the meter records two registers. On a smart meter there can be three — day, night and peak — each with its own rate and its own block of hours. This is the only part of the bill that moves with how much electricity you actually use.

2. The standing charge. A fixed daily or annual amount charged for being connected at all, regardless of consumption. It covers a share of network costs and the supplier’s cost to serve. It is typically shown as a per-day figure, which makes it look trivial; multiplied out it runs to well over a hundred euro a year, and the spread between the cheapest and dearest supplier is itself worth over €100 annually. If you use very little electricity, the standing charge can be a larger share of your bill than the electricity is. Our standing charges guide goes into why it exists and how to weigh it.

3. The PSO levy. The Public Service Obligation levy is set annually by the Commission for Regulation of Utilities, not by your supplier. It is the same on every plan from every supplier — currently around €19 a year including VAT, or roughly €1.59 a month — so it can never be a reason to choose one supplier over another. It also cannot be discounted, which matters when you are reading an advertised “X% off” claim. There is a full guide to the PSO levy if you want to know what it funds and why it has been positive some years and negative in others.

4. VAT. Domestic electricity and gas carry the reduced 9% VAT rate, extended in Budget 2026 to the end of 2030. Suppliers differ in whether the rates they advertise are shown including or excluding VAT, which is a common source of confusion when comparing two websites by hand. Every figure on our electricity comparison is VAT-inclusive so the numbers are directly comparable.

Reading the consumption section

Below the charges, the bill shows how the kWh figure was arrived at: an opening reading, a closing reading, and the difference. The critical detail is the letter or word beside each reading.

• A or Actual — the meter was physically read, or a smart meter reported.
• E or Estimated — nobody read the meter; the supplier applied a profile based on your history and the time of year.
• C or Customer — you submitted the reading yourself.

An estimated bill is not a bill for electricity you did not use; it is a guess that gets corrected at the next actual read. But a run of estimates can drift a long way from reality, especially if your usage has changed — a new heat pump, a new baby, someone working from home. If two or three consecutive bills are estimated, submit a reading. Most suppliers accept them through an app or a web form, and the correction is applied on the next bill.

Where the discount actually lands

Irish suppliers advertise discounts in two different ways, and they are not equivalent.

A discount applied to unit rates only reduces the unit charge line and nothing else. Your standing charge and the PSO levy are unaffected. A discount applied to the total bill reduces the unit charges and the standing charge — but still not the PSO levy, which is a pass-through and cannot legally be discounted.

For a heavy user the difference is modest. For a light user, a “25% off your bill” offer is worth appreciably more than “25% off unit rates”, because the standing charge is a bigger share of what they pay. When we estimate annual costs we apply each supplier’s discount to whichever base their terms specify, which is one of the reasons our ranking sometimes differs from a straight sort of advertised percentages.

Cashback is different again. It is a one-off credit — often €50 to €150 — applied after a qualifying period, usually a couple of months in. It flatters the first year and does nothing thereafter, so we count it in the first-year figure and exclude it from ongoing cost.

Estimated versus actual: what to do about a shock bill

If a bill arrives far higher than usual, work through it in this order:

1. Check the read type. If it says Estimated, submit an actual reading before doing anything else. A catch-up bill after a long estimated run is the single most common cause.
2. Check the period. Some bills cover two months and some cover three; a quarterly bill next to a bi-monthly one is not a like-for-like comparison.
3. Check whether the discount expired. Twelve months after you signed up, the introductory discount lapses and the same consumption costs meaningfully more. This is not an error, and it is the point at which you should be comparing again.
4. Check for a standing-charge or unit-rate change. Suppliers must notify you of price changes, but the notification is easy to miss.

Direct debit, level pay and budget plans

Many households pay a flat monthly amount rather than the bill as issued. This smooths winter, but it means the amount leaving your account has no direct relationship to the bill in front of you — you can be building a credit balance in summer and burning it in winter. Read the balance line, not the direct-debit amount, to know where you actually stand. Suppliers review and reset the monthly figure periodically; if you are heavily in credit in spring, ask for a review.

What a bill will not tell you

Your bill will never tell you whether you are on a competitive tariff, and it will not tell you that your discount has ended unless you read the small print. That is what comparison is for. Take your annual kWh figure from the consumption summary, enter it on the electricity comparison, and read the ongoing column as well as the first-year one. If you are ready to move, the switching guide sets out exactly what happens next.