Travel and keeping in touch are often a difficult pairing to balance. In today’s world of the Internet, many people are able to use Skype as their away-game in communications, and that’s fine if you’re communicating from a hotel or hospitality location where you have Internet access. If you aren’t, and in particular if you expect to be reachable while on the move even in some distant land, you’re likely to think “mobile phone!”

People who travel internationally for personal or business reasons often expect to be able to use a mobile phone. For some, it’s a way to keep in touch with home, for some a way of connecting with their transportation locally, and for many it’s a simple question of feeling secure that they can get in touch with somebody if they’re lost or need help. Since practically everyone has a cellphone, many will simply expect it to work where they are going. It’s not that simple. If you expect to have a cellphone overseas, particularly a smartphone, then you need to do some careful planning to avoid a range of unfavorable outcomes ranging from no service when you need it to astronomical bills.

Most US cellphones on monthly bill or “postpay” plans will support some sort of international roaming, and many prepay plans will offer at least limited roaming use in adjacent areas like Canada, Mexico, and the Caribbean. That means that if you’re in these areas, you probably will have some service for at least voice calls, but it’s important to check to see what rate you’ll be charged. In some cases, particularly for data plans, it may raise your eyebrows and blood pressure! But even these plans may not cover you in oddball locations where the operator you have doesn’t have a roaming agreement in place.

Besides the billing question, which I’ll return to in a bit, the starting point for consideration on international roaming is the type of phone you have. US phones are typically either CDMA (Verizon is the big example, but Sprint and others also use this) or GSM (AT&T and T-Mobile). The so-called “4G” LTE technology converges the two sets of standards and its adoption will eventually make all phones theoretically compatible worldwide—but adoption could be a long road, again especially in those remote locations. Internationally most phones are GSM, so you can expect that taking a CDMA phone out of the US is likely to reduce chances of the thing working to near-zero pretty quickly. In theory, GSM phones will work nearly everywhere, but you have to look to your plan to find out for sure.

A lot of people go wrong very quickly by looking on their carrier website, seeing “International calling to a hundred (or two, or three hundred) countries” as a feature. Yeah, but that means calling FROM the US TO these countries, which means the phone is in the US. What you need if you’re traveling isn’t international calling but international ROAMING. You may or may not have that, and if you have it there may be a special plan that offers you, for a fixed price per month, international roaming at a lower cost. Look into the charges both ways. Obviously the more travel you do, the better a special plan might look.

Suppose that your GSM provider’s plan really stinks, or that you have a CDMA phone that isn’t supported at all where you’re going. What are your options? Obviously one is not to carry a mobile phone, but you’ve had that option all along and you don’t like it or you wouldn’t be reading this. The real options are simple. First, you need a GSM phone that’s “unlocked”, meaning that it will accept a little “personality card” that’s called a SIM card. Then you either get a “country SIM” for the country you’re going to, or you get an international global SIM.

Let’s start with the unlocked GSM phone. All GSM phones accept SIM cards, but not all of them either let you get to the card to change it, or work after you have. That’s especially likely if you have a US smartphone that’s partially subsidized by your network operator—which most smartphones are. You could try taking the SIM out of your current GSM phone (in which case you may break it, void the warranty, etc.) or you can bite the bullet and get an “unlocked” GSM phone, meaning one that’s not locked into a specific carrier. That’s the option I recommend. One source of these is online at places like Amazon, and another is a site that specializes in global SIM cards and country SIM cards and unlocked phones. Let’s leave where you got the phone aside for a moment and focus on the choice of country versus global SIMs.  The best global phones will be described something like this:  "quad-band GSM cell phone compatible with 850/900/1800/1900 frequencies and US/International 3G compatibility via 900/1900/2100 UMTS/HSDPA".

A country SIM will work where it’s targeted, works by making you essentially a prepay customer of a local carrier. Your SIM will have a specific number of minutes or dollars or local currency on it, and as you use it you deplete the reserve, just like a prepay phone here in the US. You can sometimes “recharge” these phones, meaning add time/money to them for more talk time. You can assume they’ll work only in their target country, and maybe only on the target carrier there (they’re issued by a carrier, like T-Mobile here in the US). In many cases, that’s great. In some, not enough. You tend to leave a lot of stranded minutes on them, and you can’t use them in the adjacent country (or in some cases in areas of the target country your carrier doesn’t serve). You sometimes get lousy service in fringe areas, and you’re stuck.

A global SIM card is a special card that lets you roam in many countries—some as many as two hundred or more. You have service in any of these countries, often from multiple carriers there. Effectively you’re like a phone user from another carrier who’s just roaming there, and like roaming in general there are cases where it may not work. Some countries are not covered, some are covered in a spotty way geographically, and some may work some days and not on others. And every global SIM is different, each with its own countries, carriers, and quirks. With all the quirks, though, a good global SIM will work nearly everywhere (certainly in places you’re likely to be traveling) and you can even switch carriers (where multiple carriers are supported) if you get bad connections. Where global SIMs don’t work, you may need to think about renting a satellite phone and paying a high per-minute charge.

One common thing about the global SIMs is that they generally work differently in placing calls. Instead of just dialing a number, you first have to dial in full international format (a plus, the country code, the area code, and the number) or in some special format (an asterisk, the country code, number and a pound sign). In either case, you hit SEND and instead of ringing you may get some strange message. Then the phone rings back, you answer, and the call you made is then connected. Some people are just unable to cope with this, and if you’re one of them plan on paying for the indulgence.

Global SIMs have different rates in every country they serve, usually different rates for calling and being called, and sometimes different rates depending on what network you’re calling from and to, whether the number is mobile or wireline, etc. In general, it costs more to call than to be called, and with some global SIMs there’s no charge for being called at all, at least in some countries.

Logic says that the best strategy would be to look at all the global SIMs, compare their rates, and pick the one whose rates are the best in the countries you plan to visit. Gosh, do I wish it were that easy! There are two issues; first, how do your friends or contacts call the global phone you’ve created by sticking your SIM in an unlocked GSM phone, and second does the darn thing really work reliably at all?

I hate to start with something that should be obvious:  Your “global phone” has a phone number. If it’s a country SIM, that phone number is in the target country, which means anyone calling it has to pay for a call to that country. That’s great for your hotel concierge who wants to tell you about your dinner reservation, but probably not so great for your spouse or kids or friends, who might pay a big charge to connect. Sometimes global SIM cards will offer a US number for your phone, a kind of dual identity, so people in the US can call at a lower rate, or for nothing. You still pay the air time according to the pricing plan you got with the SIM. Most of the time, calling that US number will mean paying an additional charge, and that cost will be levied against you as the global phone user, not against the caller. These kinds of “alter ego” numbers may be available in countries outside the US too.  Most global SIM companies will provide you a table or file that shows what charges will be depending on where you are and what country is calling you or being called.  If you expect to do a lot of calling or being called a lot, check the rates carefully.

If you can’t get a US number (country SIMs almost never have them and many global SIMs don’t either) or if the rates are too high, you have some other options for letting people call you. The easiest is to use Skype. Skype international calling is typically cheaper than normal phone calling, and so if your friends and family are Skype-literate they can simply call you from Skype. Even here you have to watch the rates; Skype charges more for calls out to a mobile number.  Skype’s calling process is also complicated; your caller will either have to be registered as a trusted number, or they’ll have to enter a trusted number and a PIN.  Also remember that when someone calls your global phone, they’re calling the country the phone number is in, not the country YOU are in!

There are plenty of international SIM cards, and I've had at least three different ones, two of which I obviously came to view as bad choices.  My current choice, which has done well for me for about three years, is GO-SIM Wireless which I've found works well in just about every country.

In many countries, incoming calls to this card are free, which is handy if you’re giving your number to a local agent or hotel. Generally it’s going to cost you between a half-buck to a buck a minute to talk in major countries and obviously more to talk if you’re in the wild somewhere. You could rack up a decent bill if you expected to do long conference calls with this kind of SIM, but if that’s the case you should probably consider something that’s country-specific. This card is for people who want to be able to use a phone pretty much anywhere they go, and I can tell you from personal experience that it has worked in every country I’ve visited—which is a lot.

A senior traveling in a foreign country, especially one that’s on their own and perhaps not in a major city where help could be found quickly, needs to think seriously about having an international phone. I would be very reluctant to travel without one, and now that I have one I take it on every single trip I take. And for the record, I received nothing from GO-SIM or anyone else in relation to this piece or anything else; I’m just a paying customer and I have always been just that.

The more you’re on your own while on an adventure trip, the more important it is that you have some way of making contact with people, in-country or back home. Look into a phone strategy before you do trips where you’re not escorted because you don’t want to find out you’re out of touch by being it!