When I first started using cell phones, roaming was a pretty easy concept. If you were in your cellular provider's local service area, near home, you weren't roaming. If you were out of town, sometimes even in your own state, you probably were roaming, often with a daily or monthly charge plus a per-minute charge, typically 99 cents per minute.
Roaming across the United States got simpler fast with the advent of national calling plans from the major cellular carriers, so these days, it's mostly world travelers who face roaming charges when placing or receiving calls -- again, typically 99 cents per minute.
But while people have gotten used to paying extra to make voice calls overseas, many are still caught by surprise when they learn their smartphone data plans don't cover a thing when they set foot outside the U.S. That became a big deal when iPhone early adopters ventured outside the country, kept checking their e-mail and browsing the web as always, and came home to AT&T bills for hundreds or even thousands of dollars of international data roaming charges. (Much of the following applies to just about any smartphone, or even to multiple carriers, but some of the specifics are about an iPhone with an AT&T contract.)
If you're an AT&T smartphone user, the company automatically sends you a text message when your phone connects to a compatible cellular carrier in a foreign country, warning you of the per-megabyte charges that apply. It explicitly says, "Unlimited domestic data rate plan does NOT apply in this location," but you'd be amazed how many people ignore this and start consuming data as if they were at home. Pricey, pricey data.
Making your phone less chatty
Of course, your phone may be configured to do so many things automatically for you that, moments after you turn it on in a foreign land, you've racked up a couple megabytes of transferred data -- unless, that is, you've done a little preparation beforehand.
My first suggestion is to turn your iPhone's Data Roaming off in Settings > General > Network before you get on the plane. Doing this can make it less flexible in moving around the U.S. from cell to cell, so I usually leave Data Roaming turned on, but you want it off before you get where you're going.
Then, turn off "push" notifications for any apps where you don't urgently need them, in Settings > Notifications. (You can also just turn notifications off entirely.) You may have grown accustomed to Facebook telling you when someone's commented on your latest photo, or Echofon alerting you to a Twitter mention, but you can probably live without them, especially when paying by the kilobyte.
After you land, turn on Data Roaming only when you need it, then turn it off again. But how do you avoid paying the $19.95/MB rate?
The monthly plan
AT&T offers a $24.99/month "international data roaming" plan that gives you up to 20MB of data in a month. If you have no such plan, all data is at the crazy $19.95/MB rate. I figure when I'm traveling there might be a few instances in which I'd need to get online, so I opted to do this for my first trip overseas with my iPhone. The clerk at our store warned me that if I got back and deactivated this feature after less than a month, to get the prorated monthly fee, the 20MB would also be prorated -- so I could not pay a week's worth of fee and use a month's worth of data, or the overage would be charged at the hefty overage rates.
While in London for a week, I mostly left data roaming turned off and relied on hotel Wi-Fi or other random open wireless networks. On a couple of occasions, though, I really needed to know where I was or where I was going, and there was no Wi-Fi available. I turned on data roaming and fired up Maps. It turns out that Maps uses data pretty sparingly, even to load the map graphic. All told, I used about 1.5MB of my 20MB that week, so I was comfortable calling AT&T when I got home and turning off the feature, prorating the monthly fee to the portion of the month.
Even if the idea of paying $25 for 20MB of data turns your stomach, I'd suggest signing up for this plan before you travel outside the U.S. A few dollars a week is worthwhile for the resulting peace of mind, in case you need to get online. (And of course larger chunks of data are available for more dollars per month, but they're not a great deal, either.)
What about voice calls?
Even as the average person uses cell phones less and less for voice, and more and more for, well, everything else, every once in a while, we still need to place or receive a phone call. That can still be pricey, too, but you won't suddenly rack up a bill for thousands of dollars.
Per-minute rates for talking on your AT&T cell phone (or for someone yammering at your voicemail, if your phone rings overseas before they get transferred) range from 79 cents/minute in Canada to $1.29/minute in the United Kingdom, and $2.49/minute in Israel.
Or, you can opt for their $5.99/month "international voice roaming" plan, which discounts minutes a bit, to 99 cents/minute for roaming in the U.K., for example. I decided I wasn't planning on talking enough to make up the monthly fee via the meager 30-cent savings per minute, and kept the $6 in my pocket. If you'll be away longer than I was, or are likely to talk on the phone more, the savings starts to add up.
I'll talk in upcoming posts about the idea of buying a SIM card for your phone in your destination country, and about ways to do your voice calls via Wi-Fi rather than paying roaming rates for voice.
For now, the key to traveling with your smartphone outside the U.S. (or outside your home country, if you're not from the U.S.) is to plan ahead, ask questions of AT&T or your provider, and be prepared with what you'll need.
If, like me, you're an AT&T subscriber, take a few minutes to explore their "international roaming" and "travel guide" features at wireless.att.com/international before your trip. Call 611 from your cell phone to ask any questions you may have, and make a written note of the time and date of your call, and who you spoke to. If you come home to any surprises due to misinformation, you'll be well prepared to dispute excess charges.