Phones and eSIM
eSIM, local SIM or roaming: what works where, what it costs and how to set it up before you land.
For a trip of one to three weeks outside your home plan's zone, a travel eSIM is usually the simplest way to get data, provided your phone supports eSIM and is not locked to a carrier. Start with the destination. Inside the EU and EEA, a plan from an operator there already works at home rates under a fair-use limit, so roaming is the option to beat. Elsewhere your carrier's rate card applies, and a daily charge multiplies by every day away. A local SIM suits a stay of a month or more, or a need for a local number, and in some countries it means showing a passport at the counter. Then read the plan terms: data size, the speed after a daily cap, hotspot rules, and whether the days count from install or from first connection. The guides here compare those terms, walk through setup before you fly, and cover Japan, Europe and VPNs.
Guides
Data storyeSIM speeds on six Japanese trains
Best ofThe best eSIM for Europe: one regional plan or per-country
Best ofHow to choose an eSIM for Japan: what to compare before you buyHead to headeSIM, local SIM or roaming: a decision by country and trip lengthBest ofVPN for travel: what to check before China and hotel wifi, and what a VPN cannot hideHead to headeSIM plans compared: price per GB, speed caps, tethering rulesHow toHow to set up an eSIM before you fly (and what to do when it fails)Questions people ask
Should I use an eSIM, a local SIM or roaming abroad?
Start with where you are going. Inside the EU and EEA, a plan from an operator there roams at home rates, so check that first. Elsewhere, a travel eSIM usually fits a trip of one to three weeks, a local SIM fits a stay of a month or more, and your carrier's day pass fits a stopover, since its daily charge multiplies by the days you are away.
How do I know if my phone supports eSIM and is unlocked?
Two checks. Look up your exact model on the phone maker's support page, and ask your carrier whether the phone is unlocked. On an iPhone, Settings, General, About shows Carrier Lock: No SIM restrictions means unlocked. Only the carrier can unlock it, which Apple says can take several days. A locked phone can install an eSIM and then refuse to connect.
When should I install a travel eSIM?
Before you fly, over Wi-Fi at home, then leave the line off until you land. On most plans the days start counting when the eSIM first connects abroad, but a few start at install, so read the activation rule first. Screenshot the QR code and the manual activation details: some providers do not let you reinstall an eSIM you deleted.
Will a travel eSIM give me a local phone number?
Usually not. Many travel eSIM plans are data only, so calls run through messaging apps and text codes from your bank keep going to your home number. Keep the home SIM switched on for texts with its data roaming off, and turn data roaming on for the travel line only. A local SIM is the option that often comes with a local number.
Is roaming free in Europe?
For a plan from an operator in the EU or EEA, yes, within a fair-use limit: calls, texts and data cost the same as at home in the 27 EU countries, Iceland, Liechtenstein and Norway, and since 1 January 2026 in Ukraine and Moldova. The UK is outside the rule, though some operators keep the benefit. A US or UK plan follows its carrier's own rate card.