The short version: read the digits left to right and include all of them. On mechanical meters, skip any figures in red or inside a red box. On a NightSaver meter, take both readings and note which is day and which is night — a 1 beside the reading means night, a 2 means day on electronic models. A smart meter is read remotely, so you rarely need to touch it; if you do, its button cycles the screen through labelled registers.
Reading done? The next job is submitting it properly — and if your bills keep arriving with an E beside the reading, see estimated readings and how to stop them.
Which electricity meter do I have?
Ireland runs on a small family of meters, and the read is different for each — so the first step is identifying yours. The tell-tales are simple: a spinning disc means mechanical, a screen means electronic, two rows of numbers (or a screen that flips between two readings) means NightSaver, and a meter fitted since the national rollout began in 2019, with a blue or yellow button that walks the display through several screens, is a smart meter.
| Meter type | What it looks like | Registers | What to write down |
|---|---|---|---|
| 24-hour mechanical | A revolving disc with one row of numbers behind glass. The last digit — or the last dial — is often red or sits in a red box. | One | Every black digit, left to right. Leave out anything in red or inside a red box. |
| 24-hour electronic | A grey box with a digital screen showing a single number, usually followed by kWh. | One | Every digit on the screen, left to right. An arrow on the display is not a decimal point — read straight through it. |
| NightSaver mechanical | Same disc-and-numbers style, but with two rows of numbers stacked on the face. | Two — day and night | Both rows in full, ignoring red digits, and a note of which row is which (see below if the face does not say). |
| NightSaver electronic | A digital screen that shows one reading at a time — press the display button to move between them. | Two — day and night | Both readings plus the little number beside each: on ESB Networks meters a 1 sits beside the night reading and a 2 beside the day reading. |
| Smart meter | A modern digital meter (fitted from 2019 on) with a blue or yellow button that cycles the screen through registers. | Total, plus up to three time bands | Usually nothing — it is read remotely. If asked, the digits before kWh on each screen, with the register label (A+T1, A+T2, A+T3) shown top-right. |
| Pay-as-you-go meter | A prepay unit with a keypad or card slot, installed by your PAYG supplier’s arrangement with ESB Networks. | Varies by vendor | The button sequence differs between Prepay Power, Pinergy and PAYG add-ons — confirm the exact steps with your supplier. |
One identification shortcut that beats squinting at the hardware: your bill already tells you. A bill with a single reading line is a 24-hour meter; separate day and night lines mean NightSaver; day, night and peak lines mean a smart meter on a time-of-use plan. The electricity bill explained guide walks through where those lines sit.
How do I read a standard 24-hour meter?
The 24-hour meter is the easy one — a single register, one number, no time bands. The whole procedure:
- Find the row of numbers — behind the glass on a mechanical meter, on the screen of an electronic one.
- Read left to right and include every digit. If the row shows 34567, the reading is 34567 — never round it, never drop a leading digit.
- Mechanical meters: ignore the red. ESB Networks’ instruction is to record the number left to right, leaving out any figures in red or surrounded by a red box. Those red positions count tenths of a unit and no Irish supplier bills them.
- Electronic meters: the arrow is not a decimal point. Some displays show a small arrow among the digits. Read straight through it — every digit on screen is part of the reading.
- Photograph the meter. A phone photo with today’s date stamps your evidence if a bill is ever disputed — the habit costs three seconds.
That reading is cumulative — the total kWh the meter has recorded since it was installed. Your supplier turns it into a bill by subtracting the previous reading, which is why one wrong digit produces one spectacular bill rather than a subtle error.
How do I read a NightSaver (day/night) meter?
A NightSaver meter is two meters in one box: a day register that records usage from 08:00 to 23:00 and a night register that records 23:00 to 08:00, each billed at a different rate. (What the tariff itself is worth is a separate question — that lives in the NightSaver guide and the NightSaver vs smart tariff comparison.) Reading it means capturing both registers and — crucially — knowing which is which.
- Electronic day/night meters: press the display button to move between the two readings. On ESB Networks meters, a small 1 appears beside the night reading and a 2 beside the day reading. Write both down with their digit labels.
- Mechanical two-row meters: record both rows in full, left to right, ignoring red digits on each. The face may mark the rows; many do not.
- If the rows are unlabelled, pull out your last bill: it prints separate day and night readings, and each row of the meter will have grown from one of them. Match the row to the bill figure it follows on from — that identifies it beyond doubt. For a typical home the day register also grows much faster, but the bill comparison is the check that cannot lie.
- Photograph both registers in one frame if you can.
The register mix-up — the most expensive mistake on this page. Submitting the night register on its own as if it were a 24-hour reading, or swapping day and night when a form asks for both, is the classic NightSaver blunder. The night figure is far smaller than a total, so the bill it produces is either rejected as implausible or badly wrong — and a wrong day/night swap bills your cheap overnight units at the day rate. Always submit both readings, labelled, and if the form only wants one number, you are on the wrong form: a NightSaver account needs the two-register option. Mixed them up already? Send a corrected pair immediately and say which is which — the next actual read trues it up.
How do I read a smart meter — and do I even need to?
Usually you don’t. Once a smart meter is installed and communicating, ESB Networks collects readings remotely: half-hourly usage if you are on a smart time-of-use or dynamic tariff, and periodic remote reads — supplier help pages describe roughly six a year — if you have the meter but a standard 24-hour plan. The whole category of torch-and-notebook homework disappears, which is one of the honest arguments in the smart meters guide. The times you might still read one by hand: a switch or move where you want your own dated evidence, a disputed bill, or a meter that has lost its network connection.
When you do, the read is a button-press cycle. The button is blue or yellow, on the front of the meter, and each press moves the screen to the next register. On the common models the sequence runs like this — press the button the stated number of times from the default screen:
| Button | Screen shows | Label on screen | Worth noting |
|---|---|---|---|
| 1 press | Date and time | — | Just confirms the meter is alive. Nothing to write down. |
| 2 presses | Total import — all your usage, every time band combined | kWh total | This is the figure that matches a 24-hour tariff. |
| 3 presses | Night register | A+ / T1 alternating, top-right | Units used in the night band. |
| 4 presses | Day register | A+ / T2 alternating, top-right | Units used in the day band. |
| 5 presses | Peak register | A+ / T3 alternating, top-right | Only meaningful if your tariff has a peak band. |
On every screen, the reading is the digits shown before kWh, read left to right, all digits included. The A+ in the label means electricity imported from the grid; T1, T2 and T3 are the time-band registers — night, day and peak respectively on this sequence. One caveat worth repeating from the suppliers’ own help pages: the sequence and labels can differ slightly between meter models. If your screen shows other codes, don’t guess — your display cycles through labelled registers, and your supplier’s app or help pages name them for your exact meter.
Which registers actually matter depends on your plan: a 24-hour tariff bills the total alone, while a time-of-use tariff bills each band at its own rate. Microgeneration households will also see export registers (A− rather than A+) in the cycle — those track what your solar sends out, not what you buy.
What about the old clock-face dial meters?
If you are picturing a meter with five little clock dials, you are picturing a museum piece. The smart rollout has replaced the old dial meters almost everywhere, and ESB Networks’ current how-to-read pages cover mechanical digit meters, electronic meters and smart meters — dials no longer appear in their instructions at all. If your home somehow still has one, treat it as a two-step job: photograph the whole face clearly and send the photo to your supplier to interpret, then ask ESB Networks about a replacement. A meter that old is well past its scheduled smart upgrade, which costs you nothing to receive.
What do I do with the reading once I have it?
A reading in your notes app does nothing until your supplier has it. The submission routes — app, website, phone line, and what to do when the website rejects a figure — have their own guide, but the short list is:
- Regular bills: submit around the date your supplier asks for reads, and any bill marked with an E beside the reading was estimated — a fresh actual read fixes it. The full story is in estimated readings.
- Switching supplier: take the reading the day you sign up, photo included — it becomes the closing read for the old account and the opening read for the new one. The rest of that process is in how to switch.
- Moving house: read the meter at both properties on moving day. The moving house guide covers who to tell and when.
- Gas too? The gas meter has its own quirks — units that are not kWh, for a start — covered in how to read a gas meter.
What mistakes make an electricity reading wrong?
Nearly every disputed “my bill is mad” case traces back to one of five reading errors. Run this checklist before you submit:
- Submitting the night register as the total. The NightSaver trap above — the single most common cause of a wildly wrong bill on a day/night meter.
- Including the red digits. On a mechanical meter, tacking the red tenths digit onto the reading multiplies your apparent usage by ten. Black digits only.
- Dropping a leading digit. The reading is all digits, left to right — 04213 is 4213, but 14213 is never 4213. Count the digits against your last bill’s reading; they should match in length.
- Treating the arrow as a decimal point. On electronic displays the arrow is a symbol, not punctuation. Read through it.
- Reading the wrong meter. In apartment blocks and shared hallways, confirm the meter is yours by matching it against the reading on your last bill before you submit — the FAQ below has the full method.
And the golden habit that makes every one of these recoverable: photograph the meter every time you read it. A camera roll of dated meter photos has settled more billing disputes than any phone queue ever will.
Where to next?
- How to submit a meter reading — getting the number to your supplier without it bouncing.
- Estimated readings — what the E on your bill means and how to stop it.
- Smart meters in Ireland — the rollout, the data, and whether to say yes.
- NightSaver explained — whether the day/night tariff still earns its keep.
- Meter read in hand and shopping around? Start with best energy in Ireland — though note matched.ie is not a CRU-accredited comparison site; the accredited comparators are listed on cru.ie, and ESB Networks’ own meter instructions live at esbnetworks.ie.
