How do SIM only plans work?

A SIM only plan is an agreement between you and the provider where you pay a fixed amount each month to access the provider’s network. It includes your allowances, such as calls, texts, and data. Essentially, you pay a monthly fee to make calls, send messages, and use a set number of gigabytes (GB). As long as you keep paying the bill, the plan remains active until you decide to cancel it.

When you order a SIM only deal from your chosen provider, you will receive a SIM card to pop into your mobile phone. The SIM card holds all your account details and connects you to the network.

How do I find the best SIM only deal for me?

  • Compare providers’ network coverage in your area. To get the most out of your SIM only deal, the provider needs to have a strong signal where you live or where you use your phone the most. Many providers have a coverage map on their website where you can enter your Eircode to check the signal strength in your locality.
  • Buy data that matches your usage. The amount of data (and sometimes the speed) varies a lot between providers. Start by matching your own needs with what’s on offer. This makes it easier to upgrade or downgrade your plan later if you find your data usage habits change.
  • Make sure the customer care suits your needs. If you prefer talking to a human when things go wrong, check that the provider offers phone support. Some budget-friendly digital networks only offer support via web chat, which might not suit everyone.
  • Choose the plan that offers you the best value for money. Prices for SIM only deals vary significantly between providers, and also depend on how much data you want and if you need 5G speeds. In other words, you can save a fair bit of money by comparing offers rather than just going with the first one you see. Use the comparison table at the top of the page to quickly find the provider that matches both your budget and your needs.

Which is the cheapest SIM only plan?

Clear Mobile Unlimited is the cheapest SIM only plan right now (checked on 29/09/2026). The cost is €0.00/month for 1 months, then €12.99/month when you sign a 0-month contract. 

Get the deal at Clear Mobile

How to sign up for a SIM only deal

  1. Compare offers in the table on this page and choose the one that suits you best.
  2. Visit the provider’s website to order the SIM only plan and add any optional extras.
  3. Choose your SIM type. If your phone supports it, you can often choose between a regular physical SIM card and an eSIM.
  4. Enter your details. 
  5. Since this is a bill pay contract, the provider will usually run a quick credit check.
  6. If everything looks good, the provider will send the SIM card to you. If you have chosen an eSIM, you will likely receive a QR code via email to activate it on your mobile instantly.
  7. If you opted for a physical SIM, it will arrive in the post. Usually, you just need to pop the SIM card into your mobile to get started, but check the instructions in the letter just in case.
  8. You’re all set. You can now start using your new SIM only deal. If the provider has their own app, it’s a good idea to download it to keep an eye on your bills and allowances.

Are there SIM only plans with unlimited data?

Yes, many providers offer SIM only deals with “unlimited” data. However, it’s important to know that many plans advertised as unlimited may still have caps hidden in the “Fair Usage Policy” (FUP). This means the provider has the right to slow down or limit your data if your monthly usage goes way above what they consider reasonable. The limit varies between providers, but it is generally quite high (often between 600 GB and 1 TB), which is far more than most people use in a month.

Some networks also limit how many gigabytes can be used at full speed. Once you’ve used a certain amount, they might throttle your speed, even if you still have “unlimited” access. Be sure to check the terms and conditions to see exactly what applies to your specific plan.

Set limit for tethering 

Some SIM only plans with unlimited data may also have a specific limit on how much data you can use for tethering (using your mobile as a hotspot for your laptop or tablet). Check if your provider has such restrictions to avoid any surprises.

Can you get a SIM only plan with no contract?

Yes, you can generally choose between a 30-day rolling contract (often referred to as “no contract”) or a longer commitment of 12, 18, or 24 months. The biggest advantage of a 30-day plan is flexibility, allowing you to change providers or cancel the plan whenever you wish (usually with 30 days’ notice). A longer contract might offer better value or include extra benefits, but you are tied in for the duration.

Please note: aSIM only with no contract can still require a notice period 

Even if you sign up for a 30-day rolling SIM only deal, there is usually still a notice period required to cancel. This is typically 30 days, so remember to check what applies in your specific case.

Can I use my SIM only plan abroad?

Yes, thanks to EU roaming regulations (“Roam Like at Home”), you can generally make calls, send texts, and use data just as you normally would when travelling within the EU/EEA. However, you might not be able to use your entire data allowance abroad. This applies particularly to plans with very large data allowances or unlimited data.

Tip! Some providers also offer roaming in the UK and USA as part of their bundles. Before you travel, it’s a good idea to check the international terms with your provider. Due to Brexit, roaming in the UK (including Northern Ireland) is technically outside the EU rules, though many Irish providers currently still include it for free.

What are the rules for roaming outside the EU?

If you want to make calls, send texts, and use data in countries outside the EU/EEA (like the USA, Australia, or Asia), you should expect to pay extra. In some cases, the costs can be quite high.

However, many providers offer special roaming add-ons or daily passes to keep costs down, so check with your provider for any deals before you fly. The rates for each country should be clearly listed on the provider’s website.

How do you switch SIM only plan and provider?

If you want to switch to a SIM only deal with another provider, you should first check your current contract status. You can normally find this by logging into your account online or on the app. Even if your minimum term has ended, you usually still need to give your current provider 30 days’ notice.

The exact process varies, but the most important part is deciding if you want to keep your number. If you do, you’ll need to ask your new provider to ‘port’ your number. You will usually need to provide them with your account number or UAN from your current provider. You can find all the necessary steps on your new provider’s website.

Frequently asked questions about SIM only deals

What does “unlimited data” on a SIM only mean?

While many SIM only deals advertise unlimited data, most providers operate under a fair usage policy (FUP). In 2026, this cap is usually around 1 TB on major networks, though some budget cards might limit you to around 150 GB or 200 GB before throttling your speed. If you’re a heavy user, look for ‘truly unlimited’ mobile plans where no such caps apply – just be sure to read the terms before you sign up
Can I keep my old mobile number if I switch to a new SIM only plan?

You can, and it’s actually very handy! Keeping your number (known as “porting”) is standard practice when moving to a new SIM only provider. Once your new card arrives in the post, you just provide your UAN (Universal Account Number) to the new network. The switch usually happens within a few hours, so you’ll be sorted without losing your contacts or missing any calls.
Do I need a specific 5G phone to get the best out of a SIM only deal?

To get those lightning-fast 5G speeds, you’ll definitely need a 5G-ready phone. By now, most SIM only deals include 5G access as standard. Even budget-friendly options give you access to the same 5G masts as the bigger networks, so you’re getting great value without sacrificing speed.
Is a 30-day SIM only rolling contract better than a 12-month commitment?

It depends on how much you value your freedom! A 30-day rolling SIM only contract is grand because you can switch providers whenever a better offer pops up. On the other hand, a 12-month SIM only commitment often comes with an introductory offer that’s a bit cheaper for the first few months. If you’re happy with your coverage, the longer contract might save you a few euro in the long run.
Will my SIM only plan work abroad in the EU and the UK?

Yes, your SIM only plan will work perfectly fine for roaming. Under current regulations, you can use your data and minutes in the EU just like you would in Dublin or Cork. Even with the UK, most Irish SIM only deals have kept Roam Like at Home active, so you’re all set for a weekend trip across the water to London or Belfast.