Quick answer
Reviewed · 4 min read
You have three main ways to use your phone abroad: your carrier’s international plan or day pass, which is easiest and keeps your number; a travel eSIM data plan, often cheaper for longer trips; or a local SIM. Many travelers now keep their U.S. line on for calls and texts and add an eSIM for data. Your phone must be unlocked for other carriers’ eSIMs.
Researched and maintained by Empyrean Travel · How we research
- Easiest
- Your carrier’s international day pass or plan
- Often cheapest
- A travel eSIM for data
- Requirement
- An unlocked, eSIM-compatible phone
- Before landing
- Turn off data roaming on your home line
What is an eSIM, and does your phone support one?
An eSIM is a digital SIM built into your phone, so you can add a mobile plan by scanning a QR code or using an app instead of inserting a plastic card. iPhones from the XS and XR onward support eSIM, as do many recent Android phones, and U.S. models of the iPhone 14 and later are eSIM-only.
To use another provider’s eSIM, your phone must be carrier-unlocked. Check your phone’s settings or ask your carrier before you buy, especially for phones bought on installment plans or issued by an employer.
How do you set up a travel eSIM?
Do the setup at home on Wi-Fi, then switch on arrival.
- Buy a plan that covers every country on your itinerary, with enough data for maps, messaging and email.
- Install it before you leave, label the lines clearly (for example “U.S.” and “Travel”) and set the travel eSIM as your data line.
- Keep your U.S. line on for calls and texts but turn off its data roaming.
- Turn on data roaming for the travel eSIM when you land; most plans start when they first connect abroad.
- Don’t delete the eSIM until the trip is over, since many can’t be reinstalled.
How do you avoid surprise roaming charges?
Most surprise bills come from data roaming on your home line. Before landing, either enroll in your carrier’s international option or turn off data roaming on that line. On day-pass plans, any use, even a background app update, can trigger the daily charge.
Ships are a special case. At sea, phones can connect to a maritime network billed at high rates, so use airplane mode with the ship’s Wi-Fi package instead. Pack the right charger and a power bank; see the carry-on only packing list.
Will two-factor codes and messaging apps still work?
Usually, if your U.S. line stays active. Texts to your U.S. number, including bank verification codes, still arrive while you are using a travel eSIM for data, though carriers differ on whether receiving texts abroad costs extra. Messaging apps and iMessage run over data, so they work on the eSIM or Wi-Fi.
Wi-Fi calling helps too: on many U.S. carriers, Wi-Fi calls to U.S. numbers are included even when you are abroad. Switch where possible from text-message codes to an authenticator app before you leave; see travel cybersecurity.
What should business travelers check before using an eSIM?
Company phones often have device management that limits adding plans, so check with IT before you buy. Some employers have international plans pooled across users, which may beat a personal eSIM. In mainland China, many foreign apps and websites are blocked, so ask IT in advance how you will reach email and work systems there.
Write down how to reach your advisor, your airline and your company’s assistance number in case your data plan fails. Our business trip packing list includes the adapters and chargers you’ll need.
Your options for staying connected abroad
Carrier day pass
Simplest
Use your plan abroad for a daily fee, typically charged only on days you use it. Easy, but adds up on long trips.
Carrier international plan
Frequent travelers
Some U.S. plans include international data, sometimes at reduced speeds. Check the terms for your destinations.
Travel eSIM
Best value for data
A data plan bought online and installed digitally, used alongside your U.S. number for calls and texts.
Local SIM or eSIM
Long stays
A local number and data at local prices; some countries require passport registration.
Pocket Wi-Fi hotspot
Families and groups
One rented device shares data with several phones and laptops, popular in Japan.
Frequently asked questions
Is a travel eSIM cheaper than an international day pass?
Can I keep my U.S. phone number with a travel eSIM?
How do I know if my phone is unlocked?
When should I install a travel eSIM?
Do I need a local SIM card abroad?
Official sources
Rules, fees and schedules change — confirm the latest details at the source before you travel.