Mobile SIM: prepaid vs postpaid

The fastest way to get an Irish phone number is a prepaid SIM: buy it in a supermarket or phone shop, top up, and you have a number in minutes with no Irish bank account, address history or credit check. Monthly prepaid deals with large data allowances are widely available from operators like GoMo, 48, Lyca Mobile, Tesco Mobile and the prepay arms of Vodafone, Three and eir — compare current offers before choosing, because pricing changes often.

Prepaid or bill pay? Prepaid (pay-as-you-go with a monthly bundle) needs nothing but a top-up and suits your first months. Bill pay (contract) usually requires an Irish bank account and address, sometimes a credit check, and ties you in for 12–24 months — worth considering later if you want a subsidised handset.

Does my phone work here? Ireland uses the same GSM bands as the rest of Europe. If your phone is unlocked, any Irish SIM or eSIM works. Phones bought on contract abroad may be carrier-locked — check before you travel.

What about EU roaming? If you already have an EU SIM, "roam like at home" rules let you use it in Ireland at domestic rates for a fair-use period — fine for your first weeks, but you will want an Irish number for landlords, employers and deliveries, because many Irish services expect one.

How do I keep my number if I switch operator? Number porting between Irish operators is free and usually completed within a day — the new operator handles it; you just provide the number.

Can I use an eSIM? Yes — the main Irish operators and several of the budget brands sell eSIMs, activated in minutes from the app with no shop visit, and an eSIM is the easiest route if your phone supports it. A travel eSIM you arrived with is fine for data, but it will not give you the Irish number that landlords, banks and delivery apps expect.

Where do I actually buy a SIM? Supermarkets (Tesco, Dunnes, Lidl), phone shops, An Post post offices (An Post Mobile is itself an operator), and petrol stations all sell starter packs — or order free SIMs from operator websites. Bring photo ID if you want the shop to register it for you; topping up works by app, card online, or shop terminals.

Phone SIM or data SIM? A standard SIM includes calls, texts and a phone number; a data-only SIM (sold for tablets, routers and dashcams) has no number and cannot receive the SMS codes Irish banks and services use — make sure you are buying a standard SIM for your phone.

One naming note: "prepay registered" on a rental listing refers to the property's electricity meter, not to phones — see the utilities guide.

Last updated: September 2026. Sources: comreg.ie (the communications regulator, including its price-comparison tool), operator websites for current bundle pricing.