Asia eSIM Guide: Regional Plan or Single-Country eSIMs for Southeast Asia, Japan and Korea

An Asia eSIM is a single data plan that works across several Asian countries, so you install it once and keep the same eSIM as you cross borders. For a Southeast Asia backpacking route it is usually the simplest choice, but no one regional plan covers every country, so check the coverage list against your route before you buy. If you are spending most of your time in one country, a single-country eSIM is often cheaper.

Last checked: 27 October 2026. Coverage, entry rules and registration rules change, so check the plan page and GOV.UK travel advice for each country before you travel.

Asia eSIM or single-country eSIMs: the short answer

• Choose a regional Asia eSIM if you are visiting three or more countries, moving quickly, or crossing borders by land, where you want data the moment you cross.
• Choose single-country eSIMs if you are spending two weeks or more in one place, or if your route includes a country your regional plan does not cover.
• Mix them if needed. Most phones hold several eSIM profiles, and you switch between them in settings.
• Keep your UK SIM for bank texts. Travel eSIMs are data only.

Which countries are covered: the four Asia plans compared

SimplySIM sells several Asia regional plans, and their coverage lists differ. This table shows the countries on the most common backpacking routes, from the coverage each plan listed on 27 October 2026.

Laos is covered by the Asia (14 areas) and Asia (20 areas) plans (Asia (20 areas) uses Unitel on 3G only). If you only need Laos, our Laos eSIM runs on Lao Telecom 5G. The Asia-20 plan also covers Australia and New Zealand. Every plan also includes some other places, such as Hong Kong and Taiwan, so open the plan page for the full list.

Which plan suits which route?

• Thailand, Vietnam, Cambodia and Laos (the classic mainland loop): Asia (14 areas) lists all four.
• Thailand, Malaysia and Singapore, or anything that includes Singapore or mainland China: Asia (20 areas) or Asia (12 areas).
• A big loop including Cambodia and Singapore: Asia (12 areas) covers both, or pair Asia (14 areas) with a cheap Singapore eSIM.
• Japan and South Korea only: the Japan and South Korea Unlimited 7 Day plan (£29.56) covers just those two.

SimplySIM Asia eSIM plans

On 27 October 2026, SimplySIM plans included:

All regional plans are on the regional and global eSIMs page. The plans start when they first connect to a network in a covered country, and hotspot use is allowed. For trips longer than a month, see our guide to long-stay eSIM plans.

Country by country: what to know

Prices are the lowest single-country plan shown on 27 October 2026. Heading further west? Nepal registers phone IMEIs on local SIMs too, and India is covered in our separate India eSIM guide.

Registration and IMEI rules in Asia

Several Asian countries now tie local SIMs to your passport or your phone's IMEI number, to fight fraud and smuggled handsets. Indonesia blocks unregistered phones on local SIMs, Nepal does the same after about 15 days, Thailand and Vietnam require passport registration for local SIMs, and China requires real-name registration in person. A data-only travel eSIM from a UK provider works on roaming, so these local SIM steps generally do not apply to it. Never buy a local SIM registered in someone else's name.

How much data to bring for Asia

Most of your data goes on maps, ride-hailing apps such as Grab, messaging, booking hostels and buses, and photos. Hostel and café Wi-Fi is common on the main backpacking routes, but it is not always reliable, and you will want mobile data on buses, ferries and border crossings. As a rough guide:

• Light use (maps, messaging, bookings, mostly on Wi-Fi): a 5GB plan for a month.
• Moderate use (social media, some video calls): 10GB to 20GB a month.
• Heavy use or working remotely: an unlimited plan, keeping in mind the 1GB a day full-speed allowance.

Our guide to how much data you need for a week abroad has more detail. You can top up if you run low.

Setting up an Asia eSIM

1. Check your phone supports eSIM and is unlocked with our compatibility checker.
2. Install the eSIM at home on Wi-Fi, especially if China is on your route.
3. When you land in your first covered country, set the eSIM as your data line and turn on data roaming for it.
4. Turn off data roaming on your UK SIM so you are not charged by your UK network.

Our dual SIM settings guide covers iPhone and Android step by step.

FAQs

What is the best eSIM for Asia?

It depends on your route. For Thailand, Vietnam, Cambodia and Laos, Asia (14 areas) lists all four. If your trip includes Singapore or mainland China, choose Asia (20 areas) or Asia (12 areas). Always compare the coverage list with your itinerary.

Is there one eSIM that covers all of Southeast Asia?

Not quite. Each of SimplySIM's Asia plans misses at least one popular country, such as Singapore, Cambodia or Laos. You can pair a regional plan with a cheap single-country eSIM to fill the gap.

Is a regional Asia eSIM cheaper than separate country eSIMs?

Often, for three or more countries, and it saves installing a new eSIM at every border. For a long stay in one country, a single-country plan is usually better value.

Does an Asia eSIM work in China?

Yes, on plans that include mainland China, such as Asia (20 areas) and Asia (12 areas). Because the data is roamed, many travellers find Google and WhatsApp work, but this is not guaranteed. Install it before you arrive.

Do I need to register an eSIM in Asia?

Not for a data-only travel eSIM on roaming. Passport and IMEI registration rules in countries such as Thailand, Vietnam, Indonesia and Nepal apply to local SIM cards.

Will an Asia eSIM give me a local phone number?

No. Travel eSIMs are data only. Use WhatsApp or LINE for calls and keep your UK SIM for texts from your bank.