Asia eSIM Plans Compared: Which Regional Tier Fits Your Route?

Match a regional eSIM to your itinerary's outliers, not to the largest number in its name. Among co:sim's Asia bundles, Asia (14 areas) omits mainland China and Singapore, Asia (20 areas) omits Cambodia and Macao, East & Southeast Asia (12) omits India, and Asia-Pacific (20, incl. AU/NZ) is the only tier that reaches Australia and New Zealand while being the only one without Taiwan.

The lists are not nested, so "buy the bigger one to be safe" fails in both directions. This guide sets out what each tier actually covers today, which single leg of a route decides between them, and what changes in the plan ladder (daily allowances, throttle speeds, top-up support) once you have picked one.

#Why doesn't one "Asia" eSIM cover all of Asia?

Each regional bundle is its own product with its own operator list, assembled from what the underlying carrier agreements allow in each market. Nothing forces those lists to line up neatly, so a country can sit inside a smaller bundle and be absent from a larger one.

That has a practical consequence for how you read a plan. The number inside a live plan name is the supplier's own "areas" label, and the URL slug is a shortener for the page — neither is a promise about how many countries you get. The coverage list printed on the plan page is the authority, and it is the thing to check against your booking confirmations before you pay.

#What exactly does each co:sim Asia tier cover?

Read the table by exception. Four of the five tiers reach Japan, South Korea, Malaysia, Thailand, Vietnam and Indonesia, so those destinations rarely decide anything. The countries that do decide are mainland China, Singapore, Taiwan, Cambodia, Macao, India and the Australia–New Zealand leg.

#Which single leg of your route decides the tier?

#Does the trip include mainland China or Singapore?

If either appears, Asia (14 areas) is out — neither is on its coverage list. Asia (20 areas), East & Southeast Asia (12) and Asia-Pacific (20, incl. AU/NZ) all carry both. A Tokyo–Shanghai–Singapore run therefore has three viable tiers and one that quietly is not.

#Does it include Taiwan, Cambodia or Macao?

Taiwan is on Asia (14 areas), Asia (20 areas) and East & Southeast Asia (12), but not on Asia-Pacific. Cambodia and Macao are on Asia (14 areas), East & Southeast Asia (12) and Asia-Pacific, but not on Asia (20 areas). A Taipei plus Siem Reap itinerary is the awkward case: only Asia (14 areas) and East & Southeast Asia (12) hold both, and only the first of those also covers Laos.

#Does it continue to Australia or New Zealand?

Asia-Pacific (20, incl. AU/NZ) is the only tier on this list that reaches either, and it also carries Israel, Kuwait and Saudi Arabia. The trade is Taiwan, Bangladesh and Laos, so an Asia trip that ends in Sydney but starts in Taipei genuinely needs two cards rather than one.

#Does it push west into Central Asia or Pakistan?

Asia (20 areas) is the broad tier that reaches Kazakhstan, Kyrgyzstan, Uzbekistan, Pakistan and Sri Lanka. If Central Asia is the whole point of the trip rather than a leg of it, the narrower Central & South Asia (5) grouping exists for exactly that shape of route.

#How much do the networks differ inside one Asia plan?

A lot, and the plan name hides it. On the Asia (20 areas) coverage list the host networks run from China Mobile and China Unicom on 5G in mainland China, NTT docomo, KDDI au and Rakuten Mobile on 5G in Japan and SK Telecom on 5G in South Korea, down to Unitel on 3G in Laos and Jazz on 4G in Pakistan. Vietnam is served by MobiFone and Vietnamobile on 4G.

That spread is the regional pattern, not a quirk of one product. The ITU reports that 5G now reaches more than half of the global population and accounts for more than a third of mobile broadband subscriptions, while coverage stays clustered in high-income countries. Scale compounds it: India alone had 1,265.73 million wireless subscribers as of March 2026, which is a very different load profile from Laos.

Practical reading: budget your data for the weakest leg, not the strongest. A 30-day fixed-GB plan that felt generous in Seoul can drain faster over 3G, because retries and re-loads cost data too.

#What changes in the plan ladder once you have chosen a tier?

Three things, and they matter more than most coverage tables admit.

Daily allowance versus fixed GB. The daily plans renew an allowance every 24 hours and then throttle rather than stop. The throttle floor is not the same everywhere: on Asia (14 areas) the 1 GB, 2 GB and 3 GB daily tiers fall back to 1 Mbps, on Asia (20 areas) to 384 Kbps, and on East & Southeast Asia (12) to 128 Kbps. One Mbps still loads maps and messaging; 128 Kbps is closer to a text-only connection.

Top-up support. Most tiers include reloadable 30-day plans you can extend without reinstalling. The 500 MB one-day entry plans on Asia (20 areas), East & Southeast Asia (12) and Southeast Asia (7) are the exception: they are non-reloadable, so that card is a single day of data and nothing more.

Validity windows. Asia-Pacific (20, incl. AU/NZ) and Southeast Asia (7) are the two tiers that reach 180 days, both selling a 50 GB / 180-day plan, and Asia-Pacific adds a 20 GB / 90-day option below it. Either suits a slow multi-month route far better than stacking 30-day cards.

All of these plans are data-only: mobile data, no phone number, so calls and texts happen over apps. Every co:sim plan page lists the host networks, the install deadline, whether validity starts at first connection or at purchase, and whether the plan can be topped up. Read those four fields on the specific plan, not on the region.

#FAQ

#Which Asia eSIM covers both mainland China and Taiwan?

Two of the regional tiers list both. East & Southeast Asia (12) carries mainland China, Hong Kong, Macao and Taiwan alongside Japan, South Korea, Singapore, Malaysia, Thailand, Vietnam, Cambodia and Indonesia. Asia (20 areas) also carries mainland China and Taiwan, and extends west to Pakistan, Sri Lanka and three Central Asian countries.

The difference between them is what else the route needs. East & Southeast Asia (12) has Cambodia and Macao; Asia (20 areas) has India, Bangladesh, Laos and the Philippines instead. Asia-Pacific (20, incl. AU/NZ) is not an answer here, because it carries mainland China but not Taiwan. Check the coverage list on the co:sim plan page against your own bookings before paying, since a single missing leg is what turns one card into two.

#Is a bigger Asia eSIM automatically safer than a smaller one?

No, and this is the most expensive assumption in regional eSIM shopping. These coverage lists are not nested, so a larger headline number does not contain everything a smaller one holds. Asia (14 areas) carries Cambodia and Macao, and Asia (20 areas) does not. Asia (20 areas) carries Taiwan, and Asia-Pacific (20, incl. AU/NZ) does not.

The reliable method is subtraction rather than addition. Write down the countries on your itinerary, open each candidate plan page, and strike out any tier whose coverage list is missing even one of them. Whatever survives is a real shortlist; only then does price per gigabyte become the deciding factor, because the cheapest plan that does not cover your third stop is not cheap.

#Do these Asia eSIMs include a phone number for local calls?

They do not. These are data-only plans: they carry mobile data, and they do not come with a phone number, so there is no dialling out and no inbound SMS on the plan itself. Calls and messages travel over apps (WhatsApp, LINE, KakaoTalk, WeChat, Signal, FaceTime) exactly as they would on hotel Wi-Fi.

That matters for one specific task: a bank or a booking platform that sends a one-time code by SMS will send it to your home number, not to the eSIM. Keep your usual SIM active for those messages and let the co:sim data plan carry everything else, which is the normal dual-SIM arrangement on any recent phone. If a service offers an authenticator app or email codes instead, set that up before you fly.

#What happens when a daily Asia plan reaches its limit?

You are throttled, not disconnected. A daily-allowance plan renews its bucket every 24 hours, and once the day's allowance is used the connection continues at a reduced speed until the next reset rather than stopping dead.

The reduced speed is the part worth comparing. On Asia (14 areas) the 1 GB, 2 GB and 3 GB daily tiers fall back to 1 Mbps, which still carries maps, messaging and a mobile boarding pass. On Asia (20 areas) the floor is 384 Kbps, and on East & Southeast Asia (12) it is 128 Kbps, which is slow enough that image-heavy pages effectively stop loading. Each co:sim plan page states its own fair-use speed, so read it on the plan you are actually buying rather than assuming a regional default.

#Will an Asia eSIM work on an iPhone bought in mainland China?

Often not, and this is a device limit rather than a plan limit. Apple's setup guidance says eSIM needs an iPhone XS, iPhone XS Max, iPhone XR or later, and that only four recent models support eSIM in China mainland: iPhone 18 Pro, iPhone 18 Pro Max, iPhone 17e and iPhone Air. In Hong Kong and Macao, certain iPhone models use two nano-SIM cards instead.

So run the checks in order: confirm the handset supports eSIM, confirm it is carrier-unlocked, then compare coverage lists. On iPhone the path is Settings, then Cellular, then Add eSIM. Android wording varies, commonly Settings, then Network & internet, then SIMs. A plan that matches your route perfectly is unusable on a device that cannot hold a second profile.

Pick the tier by the leg that nearly gets left out, install at home on Wi-Fi, and let it attach on arrival. Browse Asia (20 areas) and the other regional tiers, or check a co:sim single-country plan if the trip is simpler than you thought.