SIM Cards and Mobile Plans in Thailand: Operators, Registration and Keeping Your Number
The Operators: Who Should You Choose?
Thailand's mobile market is effectively a duopoly: AIS has the largest subscriber base and the strongest coverage reputation; True, after absorbing dtac in 2023, matches it in scale and often beats it on urban value. State-owned NT holds a small share. In Bangkok and major cities the AIS/True experience is nearly identical; AIS has a slight edge on remote islands and in the mountains. All support 5G and eSIM.
Where to Buy
- Airport counters: instant setup after immigration, tourist bundles with generous data — and the highest prices. Fine if you value convenience
- Operator shops (AIS Shop / True Shop in malls): the full menu — eSIM, ownership transfer, upgrades to long-term plans. Best for anything beyond a basic SIM
- 7-Eleven: the cheapest prepaid SIMs, from a few dozen baht, but you activate data packages yourself in the app
Whatever the channel, NBTC rules require every SIM to be registered against your passport. An unregistered SIM is non-compliant and can be cut off at any time.
Tourist SIM vs Long-Stay Options
| Type | Best for | Notes |
|---|---|---|
| Tourist SIM | Stays of 8-30 days | Preloaded data bundle; data expires at the end, and the number is not meant to be kept long-term |
| Standard prepaid | Residents with light usage | Flexible top-ups and data add-ons; watch the number-validity rules below |
| Postpaid | Long-term residents, heavy data | 300-1,000+ THB/month with better value; foreigners typically need a passport plus a long-stay visa or work permit, sometimes a deposit |
How Prepaid Numbers Stay Alive
A prepaid number is not yours forever: each top-up extends its validity (larger top-ups extend longer, with slight differences between operators), and a number left without top-ups is suspended and eventually recycled. In Thailand your phone number anchors your banking app, PromptPay transfers, delivery and ride-hailing accounts and every OTP — losing the number costs far more than the airtime. Long-stay users should set a top-up reminder every two to three months, or simply switch to postpaid.
Why Your SIM and Bank Account Must Match Names
This is the core of Thailand's recent anti-scam rules: banks are required to verify that the mobile number linked to mobile banking is registered to the same person as the account. Mismatches can trigger a deadline to correct the registration, after which mobile banking is restricted. The practical takeaway: never run your banking app on a SIM registered to someone else — register with your own passport from day one. See our Thai bank account guide. Relatedly, there is a cap on how many numbers one person may register before extra verification kicks in.
Topping Up and Buying Data
- Operator apps (My AIS / True App): card or TrueMoney top-ups and the easiest way to buy data packages, with English interfaces
- 7-Eleven checkout: give your number, pay cash — works nationwide
- Data packages split into "unlimited but throttled" and "full-speed quota" types; read the fair-usage terms before buying
FAQ
How do I stay reachable between landing and getting a local SIM?
Enable international roaming on your home SIM as a bridge, or grab a tourist SIM at the airport and migrate to a long-term plan later. If you've booked an airport pickup, drivers typically coordinate via WhatsApp rather than a Thai number — see our Bangkok airport transfer guide.
Can a tourist SIM be converted to a long-term plan?
Usually yes. Take your passport to an operator shop to convert it to standard prepaid or postpaid while keeping the number. Don't wait until the SIM has fully expired if you want to keep that number.
My Thai number was suspended while I was abroad — can I recover it?
Contact the operator first: a suspended-but-not-recycled number can usually be revived with a top-up. Once recycling has begun, recovery is unlikely — move quickly to re-bind your banking apps and PromptPay to a new number and notify your bank. Before long trips away, load extra validity or enable auto top-up.
Need Help?
TaiHuBang helps newly arrived clients settle in: airport pickups can include SIM card setup and bank appointment assistance, with long-stay advice along the way. See our airport transfer and charter service, or submit an inquiry — a consultant will reply within 24 hours.