Staying Connected Abroad: eSIMs, Local SIMs, and VPNs Explained
Land with data working, keep your home accounts reachable, and stop paying roaming rates for the privilege.
By Vaughn Bullard · · 4 min read
Affiliate disclosure: this guide covers a category where Past Customs has or may add affiliate links. If you sign up through one, Past Customs may earn a commission at no extra cost to you. Full disclosure.
A phone that works on arrival changes the whole first day. You can call a car, read a map, message the person meeting you, and translate the sign in front of you. A phone that does not work turns a short trip from the airport into a negotiation.
There are three tools worth understanding: the eSIM, the local SIM, and the VPN. They solve different problems, and most people abroad end up using all three.
Check your phone first
Before anything else, confirm two things. Is your phone carrier-unlocked? A locked phone will only work with the carrier that sold it, which defeats the point. And does your phone support eSIM? Most recent models do, but not all, and some regional versions differ. Your carrier can unlock an eligible phone, and the phone's settings will tell you whether eSIM is supported. Do both at home.
The eSIM
An eSIM is a digital SIM card. You buy a data plan online, scan a QR code or tap an install link, and your phone downloads a profile. No plastic, no kiosk, no hunting for a paper clip.
What it is good for: data on arrival, short stays, travel across several countries, and keeping your home SIM active in the same phone for calls and texts.
What to watch: many travel eSIMs are data-only, with no local phone number. Plans are sold by data amount and validity period, so read both. Coverage depends on which local network the eSIM provider uses; check that before buying. Install the eSIM before you leave, while you have reliable Wi-Fi, and switch it on when you land.
The local SIM
A local SIM or local eSIM from a domestic carrier gives you a local phone number. That number turns out to matter more than people expect. Delivery apps, building access systems, restaurant bookings, clinics, and messaging with locals often assume one.
Getting one usually means visiting a carrier shop or an authorized seller with your passport. Requirements and plan types vary by country and change from time to time, so ask at the shop what they need. Prepaid plans are normally the simplest place to start.
A common setup: a travel eSIM for the first few days, then a local number once you are on the ground and know which carrier works best in your neighborhood.
Keeping your US number
Your US number is how your bank, your doctor, and half your accounts reach you. Losing it can lock you out of things that matter. Options include keeping a low-cost US plan active, or porting the number to a service that can keep receiving texts and calls over data. Whichever you choose, test it from abroad before you rely on it, especially for bank verification codes.
The VPN
A VPN, or virtual private network, sends your internet traffic through an encrypted tunnel to a server somewhere else. It does two useful things for people abroad.
It protects you on networks you do not control. Hotel Wi-Fi, café Wi-Fi, and airport Wi-Fi are convenient and not always trustworthy. A VPN makes it much harder for anyone on the same network to see what you are doing.
It can make you appear to be at home. Set the VPN to a US server, and many US services treat you as a US visitor. That can help with banking sites that are nervous about foreign logins and with services that are only available in the US.
What a VPN does not do
It does not make you anonymous. It does not override a service's terms of use; streaming platforms in particular restrict access by region and may block VPN traffic, and what they allow is up to them. Some banks flag VPN traffic as suspicious. And a VPN does not make anything legal that is otherwise not; check local rules on VPN use where you are, because they vary by country.
Choosing a VPN
Look for a provider with a clear, independently audited no-logs policy, servers in the US and the regions you care about, apps for every device you own, and a refund window long enough to test it properly. Free VPNs have to make money somehow, often from your data. Pay for one.
Test it before you travel: connect to a US server and log in to your bank, your email, and whatever else you use daily. Find out at home which services object.
A connectivity checklist
- Unlock your phone and confirm eSIM support.
- Buy and install a travel eSIM before departure.
- Decide how you will keep your US number receiving texts.
- Install a paid VPN on your phone and laptop and test it with your bank.
- Download offline maps for your arrival city.
- Get a local number once you arrive, if you will be staying more than a short trip.
Where this site stands
The Toolkit lists eSIM and VPN as categories. Specific providers will be added only after they have been checked properly, and any affiliate link will be clearly labeled. For now there are no provider links here, on purpose.
The short version
Unlocked phone, eSIM installed before you fly, a plan for your US number, a paid VPN tested at home, and a local number once you are settled into a routine. Plans, coverage, and prices change often, so check current details with each provider before you buy.
General information only, not financial, legal, tax, insurance, or medical advice. Prices, rules, and terms change; check current details with the provider or an official source.
