I will be visiting Ireland (Republic of Ireland and Northern Ireland) this summer (first trip in Europe!) and I'm from Canada.

We want to be able to use our (unlocked) Smartphones in Ireland for:

  1. GPS travelling (we are touring the whole island)
  2. Internet (I will need at least 4 GB of data)
  3. Local phone calls and texts

I have a Samsung Galaxy S7 Edge and a Samsung Galaxy S9 Plus (both unlocked). I checked some plans online and I'm not sure I can use the data/GPS in Republic of Ireland (Europe) and Northern Ireland (UK).

What would be the best course of action for my needs? Can I do it while in Canada?

  • Your local carrier may have an international roaming plan; check with them first for pricing. Otherwise you should be able to get a local sim when you arrive. Mar 4, 2019 at 21:17
  • There are no longer any differences in how cellphones work worldwide. You can use pretty much any smartphone in any country.
    – JonathanReez
    Mar 4, 2019 at 21:22
  • 2
    @JonathanReez Some major cell phone providers in the US still use CDMA, so you are overstating the possibilities
    – Peter M
    Mar 4, 2019 at 21:23
  • While @RoddyoftheFrozenPeas is right about roaming on your current carrier, be careful how it is applied as roaming charges can be expensive.
    – Peter M
    Mar 4, 2019 at 21:25
  • @PeterM the vast majority of smartphones support 3G/4G in addition to CDMA, if they support CDMA in the first place.
    – JonathanReez
    Mar 4, 2019 at 21:28

2 Answers 2


There are two sides to this.

The first side is frequency bands, the US uses different bads to europe. Top of the line smartphones will usually support a wider range of frequency bands than lower end models. If you take a recent US smartphone to Europe or vice-versa it will probablly work on 3G but has less chance of getting 4G.

The second side is what to do about service, there are two routes.

The first is to get a European roaming deal (you don't want to pay non-deal roaming rates) from your canadian provider. This means you keep your canadian number (which may be a benefit or a drawback) and you can just use your phone immediately you get off the plane. The downside is the prices can be quite high, for example bell canada's "roam better with home data" plan is $12 per day.

The other option would be to get a local pay as you go deal. You can buy the sims in many places and activate/top up with a credit card easilly enough, but afaict you can't do it until you actually get there.

Also complicating this is that you are visiting two different countries. The EU has abolished roaming charges within the EU, but the rules are intended for people who live in one EU country and visit another, carriers can (and sometimes do) terminate people whose roaming usage forms too great a proportion of the total.

And a final wrinkle is brexit, noone knows for sure how it's going to play out and what if any effect it will have on roaming between UK and Irish networks.


I'm not very sure regarding the Republic side of things, but if by some luck your first destination is the UK (Northern Ireland) then I can recommend getting a PAYG (Pay As You Go) Three sim card. You should be able to just find it in shops. Once you have it, you can either top up online (I believe you should be able to access three.co.uk for that even without any credit on your sim), or by visiting Three's branch/shops that have green Top-up logo.

At the time of writing this, you can convert your money into the following addons:

  • £10 - 2GB
  • £15 - 5GB
  • £20 - 12GB
  • £27.50 - 36GB
  • £35 - Unlimited in the UK (it's actually 2TB).

All of the above include unlimited local phone calls/texts and last 30 days.

Now for the major benefit of the SIM, you can use up to 15GB of data from the available allowance while traveling abroad in the EU, i.e. to the Republic of Ireland! (can use up to 12GB in the USA even!)

Three even confirmed in case of Brexit their free roaming in 71 countries policy will not change.

Regarding device compatibility, it is true that networks are different in Americas and elsewhere. Three UK uses the following frequencies:

  • Band 20 | 800MHz for 4G
  • Band 3 | 1800MHz for 4G
  • Band 1 | 2100MHz for 3G

Looking at gsmarena.com, Samsung Galaxy S7 Edge seems to support all the above bands/frequencies, same goes for Samsung Galaxy S9 Plus . So unless those phones sold in Canada have different specs than what gsmarena mentions, you should be fine to use Three sims in the UK (Northern Ireland)!

For the Republic specifically, Three also exists there and from browsing at their website, I believe you can get a prepay SIM with unlimited data for €20 (8GB of which you can use in the EU, i.e. Northern Ireland - not sure about the Brexit situation this way around).

Frequencies used by Three IE (couldn't find the bands though):

  • 800MHz & 1800MHz for 4G
  • 2100MHz & 900MHz for 3G
  • 900MHz & 1800MHz for 2G

Enjoy the holiday!

  • What turned me off three PAYG a few years back was that I couldn't get tethering to work. Apparently they don't let you use your regular PAYG data for tethering and the site for buying tethering addons seemed to be broken. I have no idea if the situation has improved since. Mar 7, 2019 at 14:23
  • @PeterGreen Interesting. I have personally not used PAYG for tethering but I do use my monthly Three sim for that. Previously, annoyingly they've started restricting tethering after 4G became popular, started with limiting it to 4GB and 8GB. Now recently they've finally scrapped the limits and you can tether all of your data even on the unlimited plan. Although in your case you couldn't use it at all, but won't be surprised if it's fixed as they have made some changes. I might be buying a PAYG next month before my travel to the US, if I do so I will report back on tethering on PAYG.
    – kiradotee
    Mar 7, 2019 at 20:55

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