Getting a Thai mobile number is one of the first practical tasks for anyone relocating, whether on a DTV, LTR, retirement extension, or corporate visa. The market is now effectively a two-player field: AIS and True Corporation, the latter formed by the 2023 merger of True and dtac. Both offer prepaid tourist SIMs, standard prepaid lines, and postpaid contracts, and both are subject to the same national regulator, the National Broadcasting and Telecommunications Commission (NBTC).
The registration rules tightened in 2026. The NBTC board approved measures limiting foreign nationals to a maximum of three SIM cards per operator, with a valid passport required at the time of registration. Photocopies or photos of a passport are no longer accepted; the original document must be presented in person at an operator branch or authorized dealer. The NBTC also approved a resolution capping SIM cards issued to foreign tourists at 60 days maximum, aligned with typical visa-on-arrival and visitor permissions, with no option to extend via top-up once that window closes. Separately, the regulator has moved to require liveness-detection biometric verification (a real-time photo and video check to confirm the registrant is physically present, not using a static image) for new SIM registrations and for existing users swapping SIMs, a response to a rise in fraud tied to mule accounts. The NBTC's liveness-detection requirement took effect nationwide on August 18, 2025, covering every new prepaid and postpaid SIM registration as well as existing customers who swap SIMs while keeping their number, and it applies to all operators via their apps, service centers, and authorized dealers.
For those without a passport in hand, the NBTC has separately approved a narrower set of alternative documents in limited cases, including foreign government-issued travel documents or certificates of identity paired with supporting Thai government paperwork, and Thailand's pink and white ID cards for individuals with special residency or undocumented status. These alternatives are the exception rather than the norm; nearly all new arrivals will register with a standard passport.
On practical logistics, most new arrivals still start with a short-term prepaid SIM. These are widely available at 7-Eleven, AIS and True retail stores, and airport kiosks, and pricing varies significantly by channel. Convenience-store and in-city retail prepaid SIMs for roughly a month of high-speed data are commonly reported in the 300-600 baht range, while airport kiosk pricing for similar 30-day unlimited-data packages commonly runs closer to 1,000-1,200 baht, a premium worth avoiding once you know where the retail stores are. International eSIM providers marketed to travelers (data-only, no local number) are another option many use before or immediately after landing, at broadly comparable cost to a local prepaid SIM, though without a Thai phone number for local banking or delivery verification.
Once settled, longer-term residents typically move to a postpaid plan for better call and data value, but this is where a work permit or long-term visa matters most. Carriers generally ask for a passport plus a valid long-term visa or work permit to open a postpaid account, and some branches will not process the switch without one. AIS's own published documentation list for postpaid registration (checked directly at aiscallcenter.ais.co.th) requires a passport plus one of the following: a work permit valid for at least three months, an employer confirmation letter less than a month old, a copy of a Thai house registration book, student ID/certification, a Thai driving license, a Thailand Elite Card, or -- notably -- a DTV visa, which AIS lists as an accepted document in its own right. AIS's official list does not mention a guarantor or security-deposit requirement, though separate reporting on branch-level practice suggests some branches still ask tourist-visa holders for a 2,000-3,000 baht deposit or a Thai guarantor; this branch-level variation has not been confirmed against AIS's official policy and may reflect discretion beyond the published rule. True has not published an equivalent public document list that could be located for this article, so treat branch-level answers as authoritative for a True application specifically. Reported AIS postpaid pricing starts around 599 baht per month for a mid-tier data allowance with unlimited local calls and 5G access where available; True offers comparable tiers.
The practical sequence for new arrivals: buy a prepaid SIM at a 7-Eleven or retail store (not the airport) on day one, then once your visa and housing are confirmed, bring your passport, visa page, and rental contract to an AIS or True store to discuss postpaid options. Because registration is now in-person only with biometric checks at most stores, budget time for the appointment rather than expecting a same-day remote or online switch.