Phone tips to help save money while abroad

The horror story goes something like this: A family returns from a trip abroad, and the glow from the vacation has barely begun to fade when a cellphone bill with hundreds — or even thousands — of dollars in international charges arrives. The phenomenon even has a name: bill shock.

Smartphones have become an indispensable part of international travel. You can use them to check in at the gate, go through borders, find your way around a foreign city and pay for breakfast at a sidewalk cafe. Now, it’s easier than ever to use your phone just as you would at home without getting a big hit to the wallet.

There are two major options: You can get a data plan directly through your phone company or you can swap out your phone’s SIM card, a small chip that stores data about you and your carrier. On newer phones, you can use an app that does the same thing. Here are some tips:

The three biggest U.S. carriers all offer some version of an all-inclusive international data plan. The prices and countries covered vary. Some take effect automatically when you cross a border, and others require you to sign up before your trip. Almost all of them send a text message detailing your options when your phone connects to a foreign network.

AT&T offers the International Day Pass for $10 a day, allowing travelers to use their phones as much as they would in the United States. AT&T automatically adds a day pass when customers with unlimited plans connect to the network in a foreign destination.

Customers with this plan can use their phones for as many days as they want, but they’ll be charged only for a maximum of 10 days per billing cycle. The plan covers about 210 destinations. (Canada and Mexico are included in unlimited plans.) Some exceptions: Cuba and the Maldives.

Verizon has a similar offer: TravelPass, which gives customers who have Unlimited Plus, Unlimited Welcome and other unlimited plans the ability to talk, text and use data for $10 per day (there is no cap on how many days you can be charged in a billing cycle), or a monthly $100 pass. The first 2GB of high-speed data each day is included; after that, travelers get unlimited data at a slower speed.

Unlimited-plan customers heading to Canada or Mexico do not need to buy TravelPass, but for all other plans, a day pass for those countries costs $5. TravelPass covers about 210 international destinations. Exceptions: Cuba and the Maldives.

T-Mobile automatically includes international coverage at no extra cost in its most popular plans, said Mike Katz, president of marketing, strategy and products. Depending on the plan, it includes unlimited texting in over 215 destinations worldwide and 5GB of high-speed data per billing cycle (but most phone calls cost 25 cents a minute). As with AT&T and Verizon, Cuba is not covered, but the Maldives is.

T-Mobile travelers needing more high-speed data or free calling can upgrade with day passes, starting at $5 (unlimited calling, and up to 512MB of high-speed data). For longer stays, a 30-day plan with up to 15GB of high-speed data costs $50.

Subscriber identity module cards — tiny, removable chips that link a phone to its owner’s network and phone number — offer another way to save money while you’re traveling, especially if you’re taking an extended trip or using a large amount of data. Instead of signing up for a U.S. provider’s international calling plan, you can buy a local SIM card, usually as part of a pay-as-yougo or prepaid package, usually at a cheaper rate. Rates vary depending on the provider, country and offerings.

If you have a newer model of phone, you probably don’t even need to swap out — and keep track of — physical SIM cards: You may have built-in eSIM capabilities instead.

Apps like Airalo provide affordable eSIM options for hundreds of destinations around the globe. Airalo’s options include Discover Plus, a global plan that includes 10 text messages, 10 calling minutes and 1GB of data, starting at $15 for seven days. There is also a regional plan (covering places like Europe), starting at $5 for seven days, and a local plan (for only one country), as low as $4.50 for seven days.

Two caveats to SIM swapping: Your phone generally must be unlocked (not tethered to a specific carrier), and you will usually receive a foreign phone number when you set up the new SIM card, so make sure to share that number with anyone who needs to contact you. (Your regular phone number will go to voicemail.) If you use an eSIM and your phone has Dual SIM Dual Standby technology, you may still be able to use your regular number.