eSIM vs local SIM: what to get for your trip to Thailand?

At BKK or Don Mueang, one queue waits for a plastic SIM from AIS, dtac or TrueMove H. The other traveller already has data: an eSIM installed before the flight. eSIM vs local SIM is not a draw. Compatible unlocked mobile: take the eSIM. Local prepaid only makes sense when the eSIM does not hold, or when you genuinely need a Thai number.

This guide compares travel eSIM and local operator SIM / eSIM for everyone: solo, couple, family, group, business, older travellers, teenagers, mobiles with no eSIM. Hosts stay the same. Detail in the network guide. Plans sit on the Thailand comparison.

Supplier links are affiliates. They do not move the eSIM verdict or catalog prices. Detail in the methodology.

eSIM or local SIM in Thailand: the verdict

Criterion	Travel eSIM	Local SIM / eSIM (AIS, dtac, TrueMove H)
Purchase	Before the flight, 2 minutes	Counter, passport, NBTC identification
BKK / DMK / HKT queue	No	Yes, desk hours
Thai number	Rare (usually data only)	Yes, useful for Grab, restaurants, Line
Host	The one written on the plan	The MNO on the desk logo
Home bank SMS	Home line kept	Risk if you remove the home SIM
Best for	5 to 21 days, no contract	Long stay, need for a local 08 number

Rule: eSIM-compatible mobile, 1 to 3 lines, 5 to 21 days: eSIM. Stay of several months, mandatory Thai number, Galaxy with no eSIM: plastic SIM. EE, Vodafone or Three roaming in Thailand remains the worst of the three, except a rare SKU that lists Thailand (French Free Max is the textbook example) or a travel pass for voice. Detail in the roaming guide.

Three eSIMs we track, useful once the phone passes the check:

Who it is for: solo, family, expats, business

Profile	Pick	Why
Solo, compatible iPhone / Pixel / Galaxy	eSIM	Maps + Grab, zero queue
Couple, two unlocked mobiles	2 eSIMs (or 1 + tethering)	Two bars. One prepaid does not save the second phone
Family, kids / tablets	Adult eSIMs + hotspot	Bank, Revolut, Monzo, PayPal and HMRC OTPs stay on the home line
Group of 5+	eSIM or pocket Wi-Fi	Five local SIMs means five queues
Business, laptop	eSIM + tethering	The BKK queue costs more than an hour of data
Older traveller, uneasy with a QR	eSIM installed at home	The desk is not simpler once the passport is out
Teens on a cheap SIM	eSIM, home data off before boarding	Light UK PAYG carries almost nothing outside Europe
Stay 3+ months, visa, admin	Local SIM	A Thai number for agencies, deliveries, local OTPs
Mobile with no eSIM	Plastic SIM or pocket Wi-Fi	The eSIM is not relevant. Check the model first

A reader who needs a local number is not "behind". They need a different tool. The rest of this guide assumes a short stay, the usual case on our catalog.

What the local SIM actually wins

Prepaid AIS / dtac / TrueMove H is not a 2010 gadget. It wins three cases, no more.

1. A Thai number. Restaurants, sometimes a local app OTP, certain bookings. The travel eSIM is almost always data only. Grab and Line also work on data.
2. A long stay. Three months in Chiang Mai: baht per GB on a local postpaid plan can win. Five days in Bangkok, no, once you count the queue.
3. No eSIM. Operator-locked Galaxy, old iPhone. The QR will not install. The eSIM compatibility tool says so before purchase, not at HKT.

The rest ("that is what my cousin in Bangkok does") is not an argument. Your cousin is a subscriber. You are a visitor.

What the eSIM wins (almost always)

Friction. Buy from the sofa. Install on home Wi-Fi. Activate on landing. No queue, no desk hours, no NBTC counter ID.

Dual SIM. iPhone and most recent Galaxy handsets: home line for the number (SMS OTP, Monzo, Revolut, high-street banks, HMRC). Thailand eSIM = data line. You no longer choose between Maps and your card verification code.

Readable host. On our side the host networks column says AIS, dtac or TrueMove H. A counter often sells "20 GB" without saying whether you will be on AIS or True once you leave the airport. Same radio possible, less information before you pay.

dtac is not dead. A TrueMove H SIM at the desk, a "dtac" eSIM SKU, an Orange Travel eSIM: three products. Do not merge them because the group is called True Corporation.

The network ranking applies to both tools. A dtac SIM on Koh Tao is not more magic than a dtac eSIM. Pick the host, not the plastic.

DATA / THAILAND

How much data for your trip in Thailand?

Three typical trips, same maths as the calculator, Southeast Asia factor. Maps, Grab, Reels or a laptop on tethering: the same gigabytes on an eSIM or a pocket Wi-Fi box. Turn off photo backup on cellular if you want the low end. Read the fair use.

A week, phone only10 GB

Estimate 8.3 GB · Maps, chat, Instagram. No Reels, no laptop.

Ten days with Reels20 GB

Estimate 16.5 GB · Same base, plus half an hour of video a day.

Two weeks with a laptop50 GB

Estimate 31.6 GB · One hour of phone tethering a day for the computer.

Open the data calculator

2026 TRAPS

Mistakes that still cost money

1. Pulling the UK SIM for « a proper local »

   You lose Monzo, Revolut, HMRC OTPs. Dual SIM: Thailand eSIM + home line. No eSIM: pocket Wi-Fi or a local SIM in the second tray, not in place of the home number.

   Check compatibility
2. Believing a 2022 article still describes dtac

   True and dtac merged. Read the live host, not a 2022 forum. AIS remains a distinct network.

   Compare Thailand eSIMs
3. Queuing at BKK for 8 days in Bangkok

   Passport, NBTC ID, sometimes 4G stock. An eSIM installed at home skips that. The local SIM wins on a long stay, not on a Songkran weekend.

   Compare Thailand eSIMs
4. Scanning the QR on a phone with no eSIM, at the airport

   The test is before you buy. Fail: plastic SIM or pocket Wi-Fi, not a QR in the queue.

   Check compatibility
5. Buying local « unlimited » without reading fair use

   Thai PAYG throttles too. Calculate the GB. Unlimited without tethering does not save a laptop.

   Calculate GB

FAQ

FAQ

eSIM or local SIM in Thailand?

Compatible unlocked phone: travel eSIM, installed before you fly. A plastic local SIM wins for a stay of several months or if you need a Thai number. Ten days in Bangkok, the eSIM wins on the queue.

Do I need a passport for an AIS, dtac or TrueMove H SIM?

Yes, NBTC ID is the rule at the prepaid counter. Passport, sometimes a photo. A travel eSIM is bought with no BKK queue. It is not the same product: data only on one side, often a local number on the other.

Is a local SIM cheaper than an eSIM?

Local PAYG can win in baht if you stay a long time. For 5 to 21 days, add the taxi, the queue and the time. The €/GB on the Thailand catalog often comes out ahead, with no desk.

Can I keep my UK number with a local SIM?

Only if the phone is dual SIM. Pulling the EE, Vodafone or Three SIM for « a proper local » drops Monzo, Revolut and HMRC OTPs. A travel eSIM leaves the home line on. That is the clean move.

Are dtac and TrueMove H the same network?

True Corporation merged True and dtac (2023). The One Network project integrated the radio in 2025. Opensignal still measures them separately: different policies and device ecosystems. Read the host written on the plan.

Where can I buy a local SIM in Bangkok or Phuket?

Airport desks (BKK, DMK, HKT, CNX) and city shops. Opening hours, passport, sometimes 4G stock only. The eSIM installs on home Wi-Fi. The desk still helps if the phone has no eSIM.

Sources

All external sources open in a new tab.

• Opensignal, Thailand Mobile Network Experience Report, August 2026.
• Subscriber identification: NBTC framework (passport at prepaid counter). Cross-check the desk display on the day.
• eSIM Giga catalog: Thailand comparison.
• Sibling guides: best mobile network in Thailand, eSIM or pocket Wi-Fi, Internet in Thailand, roaming or eSIM.

A travel eSIM and a local SIM often ride the same MNOs. What changes is the queue, the number, and the bank SMS. Once the phone is compatible and the stay is short, we stay on the eSIM.