Using your iphone in Europe

What do you want to do with a phone? The sim card does the communication with the local phone network. It does not affect your photo storage.

We have been to Europe 6 times since 2011. In that time, a total of about 6 months, we have never made a single phone call. In one case, I needed to unfreeze my debit card, and I used the hotel phone to call collect to the US. ALL other phone use is either WiFi to access data for the internet, email, or lately Whatsapp.

You don't need a European sim card unless you want to make phone calls.

Who is your provider at home?

My provider is AT&T

On the other hand, I use my iPhone rather frequently while in Europe, especially to call restaurants to make reservations. I also appreciate knowing that family (some older, with health challenges) can always reach me without having to try to figure out WhatsApp. I have only gotten a sim card once, while in Israel, but have opted instead for my local carrier's (Verizon's) international plan. I do recall that my photos stayed on my phone when I had the Israeli sim card. I appreciate your question, because I, too, am very non-techy!

I would by the International Plan from AT&T

Yes, you do need a SIM card. For data access on the go. Maybe never a phone call. If you leave it to Wi-Fi you need to find Wi-Fi. That is way less convenient than having data on the fly just like you use at home.
What data? Who is X artist you are looking at in a museum. Where is the closet bathroom. Directions.
What does this word mean. Translations. Getting tickets. A myriad of things you will be able to look up. What do you use your phone for at home?
We often stay at places where you have to contact the property in order to gain access to the room. In fact that was my impetus to buy a smart phone. Using email, finding Wi-Fi to do so while on the move, not so good.
With a 10gb data plan you should be good for at least a month in my experience. And that is with accessing data freely and when you want.
Changing out a SIM card is very easy. You learned your iPhone, so you can go forward from there. Did you ever want to go back to a landline? No. So you can conquer this new tech travel world.

The only thing a sim card does is connect you to a local carrier. Nothing is stored on it. You will have a different phone number as well. It doesn't affect anything else on the phone.

We never do the new sim card, but we can still use our phone when we have wifi.

If you have T-Mobile, I understand they can do Europe.

I’m in the same boat, traveling from USA, need phone to navigate and make reservations etc… I assume I need a SIM card for that correct?

Your phone will work on WiFI anywhere with or without mobile service or a SIM card. But having mobile service away from WiFi makes a smart phone far more useful.

If you are from the US and have Verizon, AT&T, or T-Mobile, you can use international roaming without needing to get a European SIM card. You are paying extra for international roaming with all three, whether you use it or not. T-Mobile doesn't charge you extra, at least.

If you don't have those three (so pay far less for mobile service at home), your mobile company probably doesn't offer international roaming, so you would then need a SIM card to use it away from WiFi. If you are wiling to do this for the occasional trip abroad, it ill save you possibly hundreds of dollars a year in mobile bills - but you do need to get that SIM, which can be kind of a PITA, especially if you are tech-challenged. But, if you are willing to work thorough i, it's very doable.

The SIM card is only for the mobile connection - not for photos, contacts, apps, or anything else on your phone. And again, if you are willing to sacrifice the incredible usefulness of having a smart phone away from WiFi - for maps, public transit info, museum times, etc. on the fly - you can still use it for free on WiFi.

If you buy a SIM card in one EU country, you should be able to use it to roam in another EU country. Scotland/UK and Switzerland are not in the EU of course, but some mobile companies still offer roaming to those countries that are "adjacent" to the EU not in it. E.g. I have a Dutch Vodafone SIM card I've been using and keeping active since 2017. I have used it in EU countries like France, Italy, Spain, Portugal, Slovenia, and Croatia (though not in the Netherlands yet!), plus I used it in the UK (while changing planes at Heathrow). And it allows roaming in Switzerland, if I ever get back there. But some SIM cards don't. Every mobile company has different rules, and every country is different. I'm not sure Vodafone UK has the same roaming rules that the Dutch version has.

So if I were landing first in Scotland for a five week trip, I'd buy a SIM card there and try to find one that will work in the other countries I will be visiting, one I can "top off" online once I leave the UK online to keep it active for the whole five weeks...or, just buy another SIM card in another country say for the final 1-2 weeks. (Many plans are good for 30 days not quite the five weeks.)

Below is some SIM card info for the UK.

https://prepaid-data-sim-card.fandom.com/wiki/United_Kingdom

Using a European SIM card also means not having access to your US phone number while you have the European SIM in place. If you want to call/text US phones for free (for Americans), sign up for Google Voice before you leave - install the Google Voice app. It gives you a second US phone number (free) and lets you call US phones, even landlines, for free with mobile data or while on WiFi. You can text US phones with it too (using the Google Voice app), using your new Google numbers.

We use the AT&T International Plan which includes unlimited data. You really don't need a different sim card unless you just want to use it.

We also use AT&T International Plan for some calls but mainly for the mapping apps, text messaging and checking train schedules. It cost 10$ per day but that is a small portion of the overall expense of the trip.

Our Iphone uses an electronic sim not a sim card. We just buy a data plan when in Europe; our usual plan allows for texting. We use the phone to make reservations, other than that we aren't using it for calls. It is very convenient with a data plan to use it for mapping when you are walking around a strange place and need to plot a course.

AT&T is my provider. It’s $10 a day, but from what I understand after 10 days you are no longer charged. So for each billing cycle you will only be charged $100 at most. The important thing is knowing when your billing cycle falls. The first time I used it I used it for 14 days and only paid $100. The second time I used it I used it for 14 days and had to pay $120. That’s because my trip overlapped a billing cycle. I like to geocache so I need the data, and I am dependent on Google Maps. I have no sense of direction.

Wow! Thank you all so much! Your feedback is very helpful, and I appreciate every reply!