Cell Phones in Portugal

Assuming the phone has the radio frequencies needed for Europe, it should work fine. Most smart phones have at least the basic GSM frequencies, but a few may not.

This may help:

http://prepaid-data-sim-card.wikia.com/wiki/Portugal

If you've never used this phone without an AT&T SIM before (unless you bought it unlocked initially), realize that you will need the unlock code from AT&T to enter in the first time you plug in a non-AT&T SIM. After you enter the code the first time, you won't need to again.

Why change the SIM? my son uses AT&T all over the EU and has never complained about cost. He does, however, have an IPad he does change the SIM for GPS but not for data. Personally, I've switched to T-Mobile which costs .20 cents a minute however, data is free.

Why change the SIM? Because AT&T charges $10/day for international use. Go to Portugal for two weeks and you're looking at $140 to use the phone. Or buy a SIM for 20 or 30 Euros. Some of us like to save money. T-Mobile works great but is too expensive for me in the US also for what I use my phone for, just to get "free international data." But I'm not part of a "family plan." If you are, then T-Mobile is a pretty good deal. It would cost me hundreds of dollars a year extra to switch to T-Mobile for the international plan; I already have a Dutch SIM I use in Europe when I travel.

No SIM is required for GPS. You don't even need mobile data for GPS, though you need MAPS to make the GPS useful as a navigational tool. The maps must be downloaded so they can be displayed on your phone or tablet. If you have mobile data on your device, then your device is probably downloading the maps needed to navigate on the fly, as needed. Some map apps like Google Maps allow you to download the maps ahead of time ("offline") on WiFi, so you don't need data to download them as you navigate.

Google Maps works reasonably well "offline" but for driving only, not for walking directions. Other map apps may support "offline" GPS navigation for walking without any mobile internet connection. But SIM cards are cheap enough that it's silly not to get one if your have a device that can use one. I have found having mobile data useful for say public transit directions while navigating European cities.

Thanks for the responses. I still have a few daze to sort this issue out. I'm off to the local AT&T store to try and get things in place. Your help is much appreciated.

You can request an unlock code online from AT&T - no need to go to a store:

https://www.att.com/esupport/article.html#!/wireless/KM1008728

They'll probably just go to their own website to do it if you go into the store. Unless you plug in some non-AT&T SIM, you won't be able to unlock it anyway. Even some SIM that isn't AT&T but works on the AT&T network (like Cricket) doesn't require an unlock code.

The biggest providers here in Portugal are MEO and NOS. They both have stores in many places, but not certain about the airport. It’s a simple matter to get a sim. They will even insert it for you in the store. You can google both providers and see the stores closest to where you are staying.

The biggest issue is if your phone isn’t paid for. Before moving two years ago, I had to pay off the phone before I could unlock my phone.

Old thread I know, but my $ .02 for those researching as I work in the telcom sector.

Modern us cell phones (eg the samsungs and iphones) generally work fine and I've found around the world, where I've had the most problem is in China, but even at that it worked ok. There are generally a multitude of channels that are used to make up the 3G/4G/LTE capabilities. There are minor variations between telecom providers sometimes, but in general things just adapt to use the fastest capabilities of your phone on the system. The short story is, don't worry about your iPhone or Samsung smartphone, it will work fine.

As for getting SIM cards.. I stopped doing that about 3 or 4 years ago as I find it to be unnecessary anymore. Most us carriers have add on plans where you can get a fixed amount of data (for example 200Mb for $40) and/or daily plans where they charge you say $10 on any given day you use voice/text/data. (if you don't use on a given day they don't charge anything). This usually works well for me.. I try to stay on wifi, but when I can't then it cost me $10 for the day. . Usually on a 2 week sightseeing trip, I'll end up with $70 or $80.

Yes you can probably find a cheap sim card, but I always find it to be a hassle. You have to find it, get your phone is unlocked before your trip and then at that I don't have access to my native voice mail. (I all ways ended up incurring charges calling back to get my voice mail). Then when i texted people it was coming from a funny number that people didn't recognize. By using the add on plan it all "just works" like I'm at home.. Its worth $10 a day to eliminate the hassle. Actually as I mentioned with a little strategy I usually don't even incur the $10 charge on many days.

There is no question you can get the local sim card and it will be slightly cheaper, but it is just another hassle I can do with out on my trip. I like things just working without any extra hassle. So unless you are ultra cost strapped, I'd skip the local sim as gone are the days of $800 roaming charges.