A travel eSIM is a digital SIM card: instead of buying a plastic SIM at your destination, you download a data plan from a local or international provider onto your phone, usually by scanning a QR code or through the provider's app. It can save you a lot compared with roaming on some US plans, and you can keep your US number active for texts and two-factor codes at the same time. It only works if your phone supports eSIM and is not carrier-locked, so check both before you buy anything.
How an eSIM works
Every phone on a cellular network needs a SIM profile: the credentials that tell a network who you are and which plan you are on. A physical SIM holds that profile on a card. An eSIM holds it on a chip built into the phone, and a phone can store several eSIM profiles, switching between them in settings.
For travel, this means you can add a second line for the trip without removing your US line. Many phones can run two lines at once, one of them for data abroad and the other your US number. Apple says iPhones with a SIM tray can use a physical SIM and an eSIM together, and supported models can have two eSIMs active at once.
Most travel eSIMs are data-only. They give you mobile internet but no local phone number, so calls and messages go through apps such as WhatsApp, FaceTime or iMessage. Some local carriers sell eSIMs with a local number too, which helps if you need to receive local calls, for example from a tour operator.
Check your phone first
Does it support eSIM?
Most recent iPhones and many recent Android phones from major brands support eSIM, but not every model or regional variant does. Look in your phone's settings for an option to add an eSIM or a cellular plan, or check the manufacturer's support pages. Apple's support pages say iPhone 14 and later models bought in the US are eSIM-only, with no SIM tray at all.
Is it carrier-locked?
A phone locked to your US carrier will only accept that carrier's service, so a travel eSIM from another provider will not work. On an iPhone, go to Settings > General > About and look at Carrier Lock: "No SIM restrictions" means you are free to use other carriers. On Android the location varies by brand; your carrier can tell you. If your phone is locked, ask your carrier about its policy for removing the lock well before you travel, because there are often conditions, such as the phone being fully paid off.
Option 1: your US carrier's international plan
The three major US carriers all sell international options, such as day passes and plans with some international roaming included. Details change, so check your own carrier's international page for the countries covered, speeds and daily or monthly terms.
Good for: short trips, travelers who want to keep using their US number normally for calls and texts, and anyone who does not want to set anything up. Watch for: daily charges that add up on long trips, reduced speeds after a data allowance, and countries not on the carrier's list. Turning on data roaming without a plan in place can lead to large charges.
Option 2: a travel eSIM
Travel eSIMs come in two kinds:
- Local carrier eSIMs, sold by a mobile network in the country you visit. They often give the most data for your money and the best coverage in that country. Some can only be bought on arrival or need ID to register.
- International eSIM providers, which resell data on partner networks in many countries. They are easy to buy before you leave, and regional plans can cover several countries on one plan, which suits a multi-country trip in Europe or Asia.
We have not tested travel eSIM providers ourselves, so we do not rank them. When comparing, look at the networks the plan uses in your destination, the data amount and validity period, whether the plan includes a local number, whether tethering (hotspot) is allowed, and the provider's refund policy if the eSIM fails to activate.
Setting it up without trouble
- Install before you fly, activate on arrival. Setup usually needs Wi-Fi. Install the eSIM at home, then switch it on when you land. Read the provider's instructions, because some plans start their validity clock at installation rather than first use.
- Label your lines (for example "US" and "Travel") so you know which one you are switching.
- Set the travel line for mobile data in your cellular settings, and turn data roaming off on your US line if you do not want US-carrier roaming charges. Apple notes that recent iOS versions may prompt you on arrival to use the travel eSIM only or both lines, and that keeping both lines on may still incur roaming fees from your home carrier.
- Keep your US line available for texts if you rely on SMS two-factor codes from your bank. Check with your carrier how incoming texts are charged abroad.
- Do not delete the eSIM until the trip is over. Removing a profile usually cannot be undone, and you may need a new one.
Which option fits your trip?
- A few days, one country, light use: your carrier's day pass or included roaming is usually the simplest.
- A week or more, heavy data use (maps, video calls, hotspot): a travel eSIM is often the better value.
- Several countries in one region: a regional eSIM saves buying one per country.
- Locked phone: your carrier's plan, or ask about removing the lock in time.
Download offline maps and keep boarding passes and booking confirmations saved on the phone in case signal is patchy when you land. If your phone is your boarding pass, a charged battery matters too: see our guide to power bank rules on planes. For the rest of your pre-trip checklist, read how early to get to the airport for an international flight, and if something goes wrong abroad, our guide on what to do if you lose your passport abroad lists the steps. When you are ready to plan, search flights for your dates.
