Ireland barely sells data-only SIMs any more. In August 2026 only two providers in our catalog carry a SIM with no calls or texts on it: Lycamobile, with four 28-day data bundles from €4.99 for 3 GB to €13 for 20 GB on Eir radio with 5G, and Three itself, whose Prepay Broadband SIM is €30 for 30 GB every 28 days on 4G. That is the whole ranking above, ordered by the cheapest monthly data-only price.
The honest advice is different. For most tablets, dongles and backup boxes the best “data-only SIM” in Ireland is a €12.99 unlimited 5G voice SIM from 48, Clear or GoMo with the calls ignored. It costs the same as Lycamobile’s 20 GB bundle, has no cap, and is €17 a month cheaper than Three’s 30 GB. Lycamobile only wins below about 10 GB a month. The rest of this page explains where each option fits: iPads, MiFi and car Wi-Fi, and a backup for when the home broadband dies.
Every data-only SIM sold in Ireland, August 2026
We count a plan as data-only when it ships with zero minutes and zero texts. Only Lycamobile and Three qualify. The ranking is ordered by the cheapest monthly data-only price, and the table adds the cost per gigabyte so you can see where the value actually sits.
| Provider · plan | Price | Data | Per GB | Cycle | 5G | Radio |
|---|---|---|---|---|---|---|
| Lycamobile Data XS | €4.99 | 3 GB | €1.66 | 28 days | Yes | Eir |
| Lycamobile Data S | €6.99 | 5 GB | €1.40 | 28 days | Yes | Eir |
| Lycamobile Data M | €9.99 | 10 GB | €1.00 | 28 days | Yes | Eir |
| Lycamobile Data L | €13 | 20 GB | €0.65 | 28 days | Yes | Eir |
| Three Prepay Broadband | €30 | 30 GB | €1.00 | 28 days | No (4G) | Three |
| For comparison: 48 / Clear / GoMo unlimited 5G | €12.99 | Unlimited (fair use) | — | Monthly | Yes | Three / Vodafone / Eir |
Two things jump out. Lycamobile Data M and Three Prepay Broadband both work out at €1 per GB, but Three gives you 4G only for three times the money. And the 48, Clear and GoMo row, which is not a data-only SIM at all, beats every line above it the moment you need more than 20 GB. Three’s SIM is a separate mobile broadband product for a dongle or hub; it is not the SIM in a Three phone plan, and Three’s own terms say it is for Republic of Ireland use only, with roaming charged on top.
What we could not list. Eir still has a legacy prepay mobile broadband SIM that community threads put at roughly €20 for 20 GB or €30 for 50 GB per 28 days, 4G only; it is not on eir.ie’s plan pages in August 2026, so we have not catalogued it. Three also sells unlimited SIM-only mobile broadband for your own router, typically €29.99 on 4G or €24.99 for 12 months then €34.99 on 5G, but it is sold through the broadband sales flow rather than a public plan page, so confirm it on the phone before you rely on it. Vodafone sells no pure data SIM: its “Data Unlimited 5G” prepay is a €20 voice plan with 100 minutes, and its data products are the 5G router and the Always Connected add-on covered below. 48, GoMo, Clear, Sky, Virgin, An Post and Tesco sell nothing data-only; Tesco’s “Data Plus 100 GB” at €15 is a prepay voice plan with 1,000 minutes.
Why a €12.99 unlimited voice SIM is usually the better data SIM
A data-only SIM used to be the cheap option because voice plans were dear. That flipped. 48, GoMo and Clear all sell unlimited 5G with calls and texts for €12.99 a month, rolling. Lycamobile’s biggest data bundle is €13 for 20 GB. You are paying one cent more to swap a 20 GB cap for no cap and to get a phone number you can ignore.
It works because none of the three prints a tethering ban. 48’s community knowledge base says outright that your 48 allowance can be used to hotspot, with nothing to enable on the account. GoMo and Clear publish fair-use and traffic-management clauses rather than a hotspot rule. The SIM goes straight into a cellular iPad, a MiFi or a 4G/5G router, or stays in your phone and shares its connection. The one caveat is the word “unlimited”: every one of these plans carries a fair-use clause that lets the network slow the heaviest users when cells are busy. Running a household’s evening streaming through a phone SIM for months is exactly what those clauses exist for. Occasional hotspotting, a laptop on the train, a tablet in the car: nobody notices.
Three is the exception on paper. Three’s All You Can Eat Data terms say the SIM is for the handset and that tethering or using the SIM as a modem is not allowed, with a right to restrict the service. In practice the hotspot works and Three community threads report no charges, but a Three voice SIM is the wrong thing to build a dongle or backup router on. If you want Three radio for data, 48 is the same masts without that clause, and Three’s own Prepay Broadband SIM is the sanctioned route.
Where Lycamobile still wins. Under 10 GB a month. A tablet that mostly lives on home Wi-Fi, a dash cam or a caravan alarm, a second SIM for a child’s iPad with no phone number attached: Data XS at €4.99 or Data S at €6.99 is half the price of anything else, with 5G and an eSIM option. Work out your real usage on how much data do I need before you pay for unlimited you will not use.
Year-one cash for the unlimited trio: 48 €155.88, Clear €155.88 (its €12.99 activation fee is cancelled by a free first month), GoMo €168.87 because of its €12.99 activation fee with no free month. Lycamobile Data L costs €169 over thirteen 28-day cycles, so the unlimited SIM is cheaper over a year than Lycamobile’s 20 GB, not just roomier.
Best SIM for an iPad or Android tablet
Any of the SIMs above works in a cellular tablet, but the eSIM question decides it for recent iPads. Since the iPad Pro (M4) and iPad Air (M2), Apple has shipped eSIM-only cellular iPads outside China, so a plastic SIM from 48, Clear or Tesco cannot go in at all. Apple’s iPad carrier list for Ireland names only Vodafone for a native in-Settings data plan. A GoMo, Three, Eir, Sky or Lycamobile eSIM QR code typically installs on an iPad the same way it does on a phone, because the profile is standard, but you are installing a phone plan on a tablet and none of those networks promises tablet support. Older iPads and every Samsung, Lenovo and Xiaomi tablet with a physical tray take any nano-SIM.
| Tablet | Cheapest sensible SIM | Why |
|---|---|---|
| iPad with a SIM tray (Air M1 and older, 10th-gen and older) | 48 Unlimited 5G €12.99, or Lycamobile Data S €6.99 under 5 GB | Plastic SIM, no fees, Three 5G, no tethering rule to worry about; Lycamobile is Eir 5G |
| eSIM-only iPad (Pro M4, Air M2 and later) | GoMo €12.99 (eSIM, Eir 5G) or Lycamobile Data M €9.99 (eSIM, Eir 5G) | 48 and Clear post plastic only; Vodafone is the only network Apple lists for iPad |
| Android tablet with a tray | 48 or Clear €12.99 | Pick by the mast that works where the tablet lives |
| A child’s tablet, no phone number wanted | Lycamobile Data XS €4.99 / Data S €6.99 | No minutes, no texts, no number to receive spam on |
Two practical notes. Apple’s own “Set Up Cellular Data” screen on an Irish iPad will push you to Vodafone; ignore it and scan a QR code from Settings › Mobile Data › Add eSIM if you bought elsewhere. And a tablet never needs 5G: a 4G SIM like 48 Student 100 GB at €10.99 (college email needed) is more than enough for video, though Virgin’s €15 4G SIM is a 12-month contract, which is a strange thing to sign for a tablet. Our full eSIM in Ireland guide has the per-network activation steps.
Best SIM for a dongle, MiFi or car Wi-Fi
Dongles and pocket MiFi units are unlocked commodities now: a 4G MiFi is €40 to €80 in Harvey Norman or on Amazon, a 5G one €150 and up, and the networks have mostly stopped bundling them. Three Prepay Broadband is the last operator product aimed squarely at this, and at €30 for 30 GB on 4G it is poor value against a €12.99 unlimited SIM in the same slot.
Our pick for a MiFi or a car hotspot is 48 at €12.99 if Three signal suits your roads, Clear at €12.99 for Vodafone masts, or GoMo at €12.99 for Eir. Three reasons. They are rolling, so a summer of caravan trips costs three months and then you stop. They carry real EU roaming (20 GB on 48, 23 GB on Clear and GoMo) so the same MiFi works on the ferry to France, where Three Prepay Broadband charges roaming on top. And they are 5G where the unit supports it. The APN is the only fiddly bit: a MiFi will not auto-configure an MVNO the way a phone does, so type it in from the provider’s help page. Lycamobile Data L at €13 is the data-only alternative if you prefer no phone number on the device, with 20 GB of EU roaming included, which is the same 20 GB as its home allowance.
Rural readers: a MiFi on a sill is not home broadband. If you are trying to replace a fixed line, the Three 5G vs Vodafone GigaCube vs Eir 5G comparison covers the proper routers with external antenna sockets and unlimited allowances, and best mobile for rural Ireland covers which mast to chase first.
Backup SIM for when the home broadband goes down
If you work from home, a backup is cheap insurance. There are three sensible shapes, and the right one depends on how often the line drops and how much you will pay to sit idle.
1. A SIM in a drawer, €0 until you need it. Buy a Lycamobile Data XS or 48 SIM, activate it, and put it in an old phone or a €50 MiFi. Lycamobile’s bundle costs €4.99 only in the 28-day windows you top it up, so an idle SIM costs nothing, though a prepay SIM that is never topped up will eventually be disconnected (see prepay expiry rules). 48 is €12.99 for any month you switch the membership on and nothing in the months you do not. Good for an outage every few months.
2. A standing €12.99 a month. Keep a 48, Clear or GoMo SIM live in a 4G/5G router with a failover setting (most TP-Link, GL.iNet and Teltonika units have one). When the fibre drops, the router swings to mobile on its own. Pick the opposite mast to your broadband’s owner: Vodafone fibre customers should back up on Three (48) or Eir (GoMo) radio, not Clear, because a Vodafone-wide fault can take both down.
3. Vodafone’s packaged answer. Vodafone fixed-broadband customers can add Always Connected, a small 4G USB stick that plugs into the Vodafone Gigabox and switches over automatically during a total outage, typically €5 a month with no minimum term. It is the only hands-off option an Irish ISP sells, it only helps Vodafone broadband customers, and it does not cover Vodafone TV or the broadband phone line. For a longer gap, a house move or a fibre order that keeps slipping, Vodafone’s 5G router on the 3-month term at €40 a month is the shortest home-broadband contract in the country; the Three 5G and Eir 5G alternatives are priced in the 5G home broadband comparison.
Whatever you pick, test it before you need it. Pull the fibre cable one evening, confirm the laptop stays online, and write the APN on a sticker on the router.
How to choose, in four lines
- Under 10 GB a month: Lycamobile Data XS €4.99 or Data S €6.99. 5G, eSIM, 28 days.
- 10 GB to unlimited: 48, Clear or GoMo at €12.99 with the calls ignored. Pick by mast, then by SIM type (GoMo for eSIM, 48 or Clear for plastic).
- A Three-branded data SIM for a dongle: Three Prepay Broadband €30 for 30 GB, 4G, if you want Three’s sanctioned product rather than 48 on the same masts.
- Backup for a Vodafone fibre line: Always Connected at typically €5 a month, or a €12.99 SIM on another network’s masts in a failover router.
Still on a voice plan and just want more data on the phone itself? That is a different question, answered on best unlimited mobile in Ireland.
Keep reading
- Best mobile in Ireland: full ranking, intro vs thereafter.
- 48 vs GoMo vs Clear: the €12.99 unlimited three-way.
- How to switch mobile: keep your number, cooling-off, ETFs.
- MVNO explained: who rides which masts.
- Find your mobile: 30-second quiz.
