A common concern of travelers is how to communicate with friends and family holding down the fort at home and traveling partners when you’re doing different activities.

Deciding on a telecom carrier based on their international plan is a smart tactic if you know you’ll be traveling beyond the United States and needing to stay connected the entire time.

Keep in mind that connecting a smartphone to wifi will give you many services you need, but you may not be able to text and call over wifi. It’s also useful to know the cost of data wherever you’re traveling.

Here’s a breakdown of the international phone plans offered by all of the major U.S. telecom carriers.

AT&T

AT&T has a variety of phone and data plans ranging from prepaid minutes, texts and data to unlimited plans. Its international plans vary almost as much as their domestic counterparts, which gives customers plenty of flexibility depending on how much they plan to use their device while abroad.

The best deal for talk and text is the $10 International Day Pass, which gives you unlimited calls within the countries that qualify for using the pass, as well as back to the U.S. The pass also gives you unlimited texts worldwide.

Your data use will count toward your monthly allowance based on your cell plan. You can use the International Day Pass in many countries but there are somewhere it won’t be an option.

In this case, your best option is probably AT&T Passport which starts at $60 and gives you 1 GB to use for talk, text, and data. This can be used one time, or monthly.

The Pay Per Use option charges $2.05 per MB of international data for talk, text, and data.

Project Fi

Project Fi, the phone service by Google and my personal favorite, has an extremely affordable and comprehensive international phone service structure. Its usual phone plan is simple and consistent no matter where or how often you travel.

In the U.S., unlimited talk and text is $20 per month. Data is $10 per GB, and you can prepay for a certain amount in your custom phone plan, but you still pay $10 per GB if you use more data than your pre-planned amount.

You will only be charged up to $60 for 6 GB of data if you’re on a single member plan, as that is when their Bill Protection policy kicks in – i.e., any data use beyond that is covered in the $60 charge. For plans with more than one member, bill protection kicks in at different amounts of data used.

Project Fi’s service is designed to be very simple and affordable, and the same is true for their international policy for using their plan. Project Fi offers full speed service in more than 170 countries, so you can stay connected around the world. Data and texts are still $10 per GB and you can make phone calls are $0.20 per minute.

The Bill Protection policy also applies internationally, which means that you won’t pay more than $60 per month for using your phone for texts and data abroad. Keep in mind that you can make calls over wifi if you’re connected, but call quality depends on your connection speed.

If you have a good wifi connection, this can be great for the countries not covered in the policy or if you’re having trouble getting a good connection over the cellular network.

If you travel often and are looking for flexibility, Project Fi will most likely give you the most bang for your buck with cheap (and consistent) pricing per minute for international phone calls while keeping the same rate for data usage you get at home.

Sprint

Sprint is known for less expensive, more customizable plans compared to primary competitors AT&T and Verizon. The same is true for its international plans, which vary based on both needs and destination.

Add the Sprint International Connect Plan to qualified plans for an extra $15 per month, which allows you to call landlines in more than 60 countries for free. There are other perks like 1 cent per minute calls to mobile phones in Mexico, and unlimited international texting to more than 180 countries.

If you primarily travel within North America, it’s worth considering the Sprint-Mexico Canada plus for $5 per month, with unlimited calls to Mexican and Canadian mobile phones and landlines, and unlimited messaging from the U.S. to 180+ countries. The Cuba 20 Plus plan (which is $10 per month) gives you 20 anytime minutes to Cuba, and discounted international calling.

T-Mobile

Stateside International Talk gives you unlimited talk and text from the U.S., Mexico, and Canada to mobile numbers in more than 30 countries. This also includes discounted international landline rates to more than 70 countries. This is a fantastic deal at $15 per month.

If you’re traveling outside of North America, rates vary per text or call minute. This makes T-Mobile’s plan the most unpredictable, but potentially more flexible for customers who have minimal needs while traveling abroad.

Data is included while traveling abroad to a wide range of different countries, but only at slower 2G speeds. There is an option to pay a fee and upgrade your speed while you’re abroad.

Verizon

Verizon’s plan, TravelPass, keeps it simple: use your plan’s talk, text, and data limits for $5 per device per day in Mexico and Canada, or $10 per device per day in more than 130 other countries. You’re only charged on the days you use your device outside of being connected to wifi, making this one of the more flexible daily rates available.

Several tiers of monthly plans are available, with separate pricing tiers for Mexico and Canada vs. more than 140 other countries. Or, opt for pay as you go with prices such as $0.50 for sending a message, $0.05 for a message received, and call prices ranging from $0.99 to $2.99 per minute.

WhatsApp

Of course, you may not always feel the need to have data coverage while you’re traveling, especially since in some countries it’s not as easy as selecting the right US-based carrier.

Luckily, in many areas around the world, wifi is very easy to find. Whatsapp is a messaging app that works both over wifi and data services and may be all you need to communicate while you travel. Better yet, it’s completely free!

Whatsapp is a free messaging app that works both over wifi and data services and may be all you need to communicate while you travel.

Bottom Line

If you travel often and are looking for flexibility, Project Fi will most likely give you the most bang for your buck with cheap (and consistent) pricing per minute for international phone calls while keeping the same rate for data usage you get at home.

AT&T customers get a great deal with the $10 International Day Pass as you can use the same data plan and know that you have the option to use your device without having to count the number of texts sent or add up all the minutes you spend connecting over the phone.

Overall, each carrier offers at least one decent international plan that will help you stay up to date with both your travel buddies and everyone back home.