Mobile

How to stay connected on the road — prepaid eSIMs you activate on landing, US cellular carriers whose plans already include data abroad, and a VPN for hotel Wi-Fi and geoblocked services from home.

There are two practical answers to the “what about my phone in Asia?” question. A prepaid eSIM is the simplest for a trip of a few weeks: pick a plan before you fly, scan the QR code, and you’re online the moment the plane touches down — no airport kiosk, no swapping cards, no language barrier. A US carrier with international roaming built in is the simplest for people who travel often: keep your existing number, skip the eSIM setup, and pay your home carrier instead of a foreign one. Either way, a VPN belongs on the same phone — it encrypts whatever hotel or café Wi-Fi you connect to, and routes traffic through a server back home so US-only streaming and banking apps keep working overseas.

eSIM

Most modern phones support eSIM, and an eSIM bought before you fly is the simplest possible answer to the mobile-data question. The plan installs as a second line on your phone — your home SIM stays in place — and switches on the moment you land. Pricing is per-GB or unlimited, by country or region, for windows from a few days to a month. The seven providers below cover most of what travelers reach for; pick on price-per-GB, coverage in your destination, and whether you want metered or unlimited data.

Cellular Carriers

Three options here, depending on how the trip is structured. A US carrier with international roaming built in is the no-setup option for people who travel often — existing number, existing app, bill from a company you already know. A local SIM bought at the destination airport is almost always cheaper for stays longer than a week or two. Picking the right local network matters less than people think — in Thailand and Vietnam the big two or three operators all have solid coverage in tourist areas — but it’s worth knowing who they are before you walk up to a kiosk.

United States

The big three (Verizon, AT&T, T-Mobile) all sell international add-ons; Spectrum Mobile is the largest MVNO that rides on Verizon’s network. Day-pass pricing is the norm: a flat fee per day you actually use data abroad, with the same domestic plan resuming when you’re home.

Thailand

After True’s 2023 merger with DTAC, Thailand is effectively a duopoly — AIS and True Corporation hold over 98% of subscribers between them, though DTAC still operates as a customer-facing brand under True. Both networks have strong 5G coverage in Bangkok, Phuket, Chiang Mai, and the major resort areas; tourist SIMs are sold at every international airport for a few hundred baht.

Vietnam

Three operators dominate Vietnam, with Viettel (military-owned) holding well over half the market and VinaPhone (state-owned VNPT) and MobiFone splitting most of the rest. Local SIMs are dirt cheap — expect a few hundred thousand dong (under $10) for several weeks of data — and Viettel and VinaPhone booths are everywhere in arrivals at Tan Son Nhat (Saigon), Noi Bai (Hanoi), and Da Nang.

Japan

Japan is a tight oligopoly — three incumbents (Docomo, KDDI’s au, SoftBank) hold ~97% of subscribers, with Rakuten Mobile the only meaningful challenger since 2020. All four run extensive 5G in the major cities and along the Shinkansen corridors; coverage diverges in rural prefectures, where Docomo is still the safe choice. Tourist eSIMs from these carriers (or via Airalo/Ubigi) are the path of least resistance — physical tourist SIMs at Narita and Kansai exist but are pricier than in Southeast Asia.

Indonesia

Indonesia is a 17,000-island archipelago, so coverage matters more here than in compact countries — Telkomsel’s state-owned reach is what most travelers default to once they leave Jakarta or Bali. The market is four-deep: Telkomsel, Indosat (formed by the 2022 Indosat–Tri merger), XL Axiata (Malaysian-owned), and Smartfren. Tourist SIMs are sold at every international airport for under $10.

Philippines

A two-and-a-half-player market: Globe and Smart (the PLDT consumer brand) split roughly 85% of subscribers, and DITO Telecommunity has taken the remaining 10–15% since launching in 2021. 5G coverage now reaches over 90% of Metro Manila and most provincial capitals, with all three carriers selling tourist SIMs at NAIA, Mactan-Cebu, and Clark airports.

VPN

A VPN does two jobs on a trip. It encrypts your traffic on untrusted Wi-Fi — hotel lobbies, airports, cafés — so login sessions and bank apps aren’t sitting in the clear on a shared network. And it lets you appear to be browsing from somewhere else, which keeps US-only streaming services, banking apps, and government sites working when you’re in Asia. The five providers below are the established names; pick on speed, server count in the country you’ll be in, and whether you want one subscription to cover the whole household or just your own phone.

See also: Staying Connected for a deeper look at eSIM, local SIM, and roaming trade-offs, and Tech Setup for what to pack alongside the phone plan.

← Back to Home