Before you begin
What you need to compare roaming and eSIM
Choose the exact current plan where it is listed. Published allowances for the named Three, 48 and GoMo plans are applied automatically; use the another-plan route if the label does not match your contract.
A provider quote is the strongest input. It replaces the built-in rate and lets the tool handle an unlisted plan or destination without guessing.
Use the final price, data allowance and activation validity of one eSIM package that is available for your destination.
Estimate data for the whole trip, not per day. Video and hotspot use can move the answer quickly.
Reading the answer
Understanding which option is cheaper for your trip
The cheaper route is recommended only when it supplies enough data for enough days and the phone can actually use it.
The break-even eSIM price is the most you could pay before the modelled Irish-network route becomes cheaper.
A small saving may not justify changing SIM settings if your Irish plan also includes calls and texts that the eSIM does not.
Boundaries
Assumptions and limitations
Working assumptions
- You use mobile data on every trip day entered; provider day passes often reset at midnight Irish time.
- Whole-trip data is spread evenly enough not to breach a daily allowance early. A provider quote overrides this assumption.
- The eSIM price is entered in euro and already includes any card or currency-conversion cost.
- EU/EEA and UK calculations use a maintained published allowance for an exact supported plan; otherwise they use the remaining allowance entered by the visitor.
Where to be careful
- Calls, SMS, voicemail and premium-number charges are not added; the comparison is for mobile data.
- Roaming promotions, account-specific discounts, spend caps and network availability can change the amount actually charged.
- The UK is not covered by the EU roaming regulation; continued inclusion is a provider choice and should be confirmed.
- Maritime, in-flight, satellite and border-network roaming are excluded.
- An eSIM can have speed, tethering, network and activation restrictions that price alone does not show.
Worked example
The same question, answered end to end
A week in the United States on a Three bill-pay SIM-only plan, needing 5 GB, against a €12 eSIM offering 5 GB over 30 days.
What was entered
- Three bill-pay SIM-only, travelling to the United States for 7 days.
- 5 GB of data needed, with no included roaming data for that destination.
- An eSIM quoted at €12 for 5 GB, valid 30 days.
- The phone is unlocked and eSIM-compatible; no ordinary calls or SMS needed.
How it is worked out
The United States is outside the EU and EEA, so Roam Like Home does not apply and the network's published roaming pricing does.
Every published combination that would cover both the 7 days and the 5 GB is priced, and the cheapest is taken — here seven daily passes.
The eSIM is checked against the trip rather than assumed to fit: 5 GB covers the data, and 30 days covers the 7-day trip.
The eSIM's €12 is subtracted from the network cost to give the saving.
The break-even price is the network cost itself — below it, a suitable eSIM is cheaper; above it, it is not.
What the tool returns
- Recommended data route
- Travel eSIM
- Irish-network data cost
- €27.93
- Quoted eSIM package
- €12.00
- Difference
- €15.93
- Trip data modelled
- 5.0 GB
Common questions
Questions about this tool
Is mobile roaming free in the EU?
Your normal allowance generally works in the EU/EEA at no extra charge, subject to fair-use limits. If you exceed the roaming allowance, a regulated surcharge may apply; the calculator uses the allowance you enter rather than assuming every plan is the same.
Is the UK still included in Irish mobile roaming plans?
Many Irish providers continue to include the UK commercially, but EU law no longer requires it. Check the current allowance shown by your provider before travelling.
Will a travel eSIM keep my Irish phone number?
On a compatible dual-SIM phone, you can normally keep the Irish line active for calls and SMS while selecting the travel eSIM for data. Incoming calls on the Irish line can still incur roaming charges outside included zones.
Are travel eSIMs data-only?
Most destination eSIMs are data-only, although some global packages include calls and texts. WhatsApp, Signal, FaceTime and other internet calling work over a data-only package.
Why do I enter the eSIM price myself?
eSIM prices and packages change frequently and can be shown in another currency. Using the live final price and allowance you can buy now is more accurate than a stale price table and keeps the recommendation independent of any affiliate relationship.
Does an affiliate relationship change the result?
No. The calculator compares the published Irish tariff or your own provider quote with the eSIM quote you enter. A future commercial link can appear only after the result and cannot alter the calculation or recommendation.