Getting a Thai SIM or eSIM as a foreigner — AIS, True and dtac plans compared, where to buy, passport registration rules, top-up methods and the best options for expats, digital nomads and DTV/LTR visa holders.
A local SIM or eSIM is one of the first things almost every arrival in Bangkok sorts out, and it's simple once you know the rules: all three major networks — AIS, True and dtac (now merged with True) — require passport registration by Thai law, and all are sold at the airport, in malls, and at 7-Eleven. Below is what each carrier offers, where to buy, how registration and top-up work, and which plan suits short stays versus a longer base in the city. For home internet once you've settled into a condo, see our Bangkok cost-of-living guide.
Thailand's largest and most extensive network by coverage, AIS is generally considered the strongest choice for reliability across Bangkok, including inside malls, condo towers and the BTS/MRT underground sections. Its tourist-focused "AIS SIM2Fly" and "Traveller SIM" packages bundle data-heavy plans for visitors, while the standard AIS prepaid and postpaid lines (One-2-Call, Fibre-linked plans) suit longer-term residents. AIS also has the widest network of physical stores for in-person support.
Best for: Anyone who wants the most reliable nationwide coverage and easy in-person support.
True runs a close second in coverage and is heavily bundled with True's other services (True Online fibre, True ID streaming), which can make it attractive if you're also setting up home internet. True's tourist SIMs and "9Val" prepaid packages are competitively priced, and True has a large retail footprint in malls and True Shops across the city.
Best for: People also getting True fibre internet at home, or who want streaming bundled in.
dtac has historically been the value option with strong urban coverage, particularly popular with budget-conscious residents and long-stay expats. Following its 2023 merger with True under the same parent company, dtac and True networks are consolidating, but dtac SIMs, plans and branding are still sold and supported separately for now. dtac's "Happy Tourist" SIM remains a common airport pickup.
Best for: Budget-focused users and those wanting straightforward prepaid top-up plans.
All three Thai carriers now offer eSIM activation, letting you buy and activate a Thailand data plan online before you even land — handy for keeping your home number active on a second slot. Third-party eSIM apps (Airalo, Holafly and similar) also sell Thailand and regional data-only eSIMs that activate instantly, though they're typically data-only (no local Thai phone number) and pricier per GB than a local carrier SIM bought in-country.
Best for: Travelers who want data working the moment they land, before buying a local SIM later.
Thailand's National Broadcasting and Telecommunications Commission (NBTC) requires every SIM — prepaid or postpaid — to be registered against a valid ID. As a foreign visitor or resident, that means your passport: bring the physical document, since staff typically need to scan the photo page or chip and take a photo for the carrier's system. Unregistered or improperly registered SIMs can be suspended, so always register through an official channel (airport kiosk, carrier shop, or supported 7-Eleven staff) rather than accepting an already-activated SIM from an unofficial reseller.
Yes. Thai law (enforced by the NBTC) requires every prepaid and postpaid SIM to be registered to a real identity document. As a foreigner, that means your passport — bring the physical passport, not just a photo, since staff typically need to scan the passport chip or photo page.
AIS generally has the strongest, most consistent coverage across Bangkok including malls, condo towers and underground BTS/MRT sections, and the widest retail network for support. True is a close second and worth considering if you're also bundling True fibre internet at home. dtac (now merged with True) remains a solid budget option. For most expats and digital nomads, AIS or True are the safer defaults; dtac suits price-sensitive users who mainly need data.
Tourist SIMs (like AIS SIM2Fly or dtac Happy Tourist) are convenient at the airport and bundle a fixed data allowance for a set number of days, but they usually work out more expensive per GB and expire quickly. If you're staying more than a couple of weeks, switching to a standard registered prepaid or postpaid plan from the same carrier is cheaper and gives ongoing top-up flexibility — most DTV, LTR and long-stay visa holders go this route within their first week.
Yes. AIS, True and dtac all sell eSIMs that can be purchased and activated online before arrival, and third-party providers (Airalo, Holafly, etc.) sell Thailand-specific or regional data eSIMs. A carrier eSIM gives you a real Thai number; most third-party eSIMs are data-only with no local number, which matters if you need a Thai number for banking, delivery apps or visa paperwork.
Top-up ("เติมเงิน") is available at 7-Eleven and most convenience stores, via the carrier's app with a linked card, at ATMs of Thai banks, or with cash at any AIS/True/dtac shop. Most long-stay users switch to an auto-renewing monthly package through the carrier app once settled, rather than manually topping up.
Look for an unlimited or high-cap data package (most carriers offer 30GB+ or truly unlimited-at-reduced-speed plans) rather than a small tourist bundle, since video calls and cloud work eat data fast. AIS and True both sell monthly SIM-only data plans well suited to DTV and LTR visa holders working remotely, and pairing one with home fibre internet (rather than relying on mobile data as your only connection) is the norm for anyone based in Bangkok longer-term.
Coworking spaces · Laptop-friendly cafes & wifi · Cost of living · DTV visa · Bangkok city hub
Primary and official sources are cited above. Government rules, fees and procedures in Thailand change over time and vary by office; always confirm current requirements with the relevant authority before relying on them. BAANLYY never takes paid placement in editorial content.
Get connected, then browse condo towers and run the numbers for your stay.
Hero photo by Silvie Lindemann on Pexels. General information, not legal or immigration advice. Carrier plans, prices and promotions change often — confirm current rates directly with AIS, True or dtac.