A Thai SIM registered to your passport is essential for banking OTPs, Grab, immigration appointments, and two-factor login. Buying a SIM is easy; choosing the right plan and store saves money and avoids early expiry.
Major carriers
| Carrier | Strengths | Watch-outs |
|---|---|---|
| AIS | Broad coverage, popular on islands | Tourist packs expire |
| True | Strong in Bangkok urban core | Shop staff quality varies |
| dtac | Competitive data promos | Coverage gaps in remote north |
There is no perfect winner — pick by coverage in your condo (test with a friend's SIM if possible).
Quick task reference: /tasks/sim
Where to buy
| Channel | Pros | Cons |
|---|---|---|
| Airport counters | Immediate data after landing | Tourist-priced packs |
| Official brand stores | Proper registration, receipts | Queues in malls |
| 7-Eleven / FamilyMart | Convenient | Staff may sell tourist packs only |
Bring passport — photo page and entry stamp. Registration is on the spot.
Tourist SIM vs long-stay plan
Tourist SIMs (often 8–15 days to 30 days) suit holidays. Long-stay holders should move to monthly prepaid or postpaid to avoid mid-extension data cutoffs.
Nomads on DTV: align plan renewal with 90-day reporting calendar so you do not lose OTP access.
eSIM in 2026
AIS, True, and dtac offer eSIM QR activation at flagship stores — useful if your phone supports dual eSIM. Airport eSIM kiosks exist; confirm 5G band support for your device model.
Tip
Screenshot your phone number and carrier app login after activation. You will need the number for bank KYC and condo internet orders.
Typical costs
| Plan type | Indicative price | Data |
|---|---|---|
| Tourist 8–15 days | ฿299–599 | 50–100GB capped |
| Monthly prepaid | ฿399–899 | 50GB+; promos change monthly |
| Postpaid with handset | Higher | Bundled contracts |
Budget line: Cost of living in Thailand 2026
Topping up
Use carrier apps (myAIS, TrueMoney), 7-Eleven counters, or bank apps. Keep ฿100–200 balance for OTP SMS even on mostly-data plans.
5G and home fibre
Mobile 5G is fast in Bangkok and Chiang Mai cores; home fibre remains primary for video calls. See utilities guide.
City hubs: Bangkok · Chiang Mai · Digital nomad cities
Banking and immigration links
Banks send OTP SMS to Thai numbers during account opening. Immigration SMS reminders exist in some offices — keep the SIM active between trips.
Opening a Thai bank account · Moving to Thailand guide
Frequently asked questions
Can I use my home country SIM?
Roaming works briefly but is expensive for daily Grab and banking OTP requirements.
One SIM for dual-SIM phone?
Common pattern: home eSIM dormant, Thai physical SIM in slot two.
Lost passport — SIM still OK?
Report to carrier with police report; number recovery depends on carrier records tied to old passport.
Is VPN needed?
Not for carrier reasons; some banking apps geo-check — Thai IP or local SIM helps.
