While you probably can. The law is written to prevent use cases like this, to avoid a race to the bottom between operators in different countries. Which makes sense since infrastructure costs can vary largely between countries, so it'd be unfair competition.

Interesting that they do this because they know infrastructure costs vary between countries but they don't give a shit about the price of electronic goods, services, etc in the single market.

If you use it for more than 120 days outside your home country your phone operator is allowed to query this and charge you.

Sure. This hasn't happened yet in all the years I've been doing this. Maybe it's because I don't use data on this card, only calls.

The relevant legislation has only been in force since 20170615 [0].

[0] https://en.wikipedia.org/wiki/European_Union_roaming_regulat...

Bkess you for using ISO 9660, my friend.

I was contemplating doing something similar, especially with eSIM on Apple Watch.

Calling you must be a bit of a pain. I just check and calling abroad from Lithuania is still 0.5 euro per minute...

No, I just have a dual-sim phone(OnePlus 5T) - for data and calls in UK I have a proper British sim. But whenever I need to call my family or anyone in Poland, I just dial from the second(Polish) sim, and call for free, using the minutes that come with my Polish contract(and they can call me for free on my Polish number as well). It's also pretty useful whenever I'm somewhere in the UK that doesn't have a good signal on my main network - then I can use the Polish sim to connect to any network that has the best signal and just use data off that card temporarily.

Then we leave EU, alas and no of the consumer friendly law applies.

Well, yes, it remains unseen what happens once brexit actually happens. But this solution works at the moment, and I can only imagine it can also work in other EU countries.

I am from Norway and we love you, Polish people. <3