On 17 October 2025, NBTC approved the Measures to Strengthen Cross-Border SMS Control, a targeted supplementary regulation developed to address the sharp surge in overseas fraudulent SMS after the implementation of the August measures. Building on the August rules, it sets more specific and stringent enforcement requirements for A2P SMS and SIM Box management.
Since the eight core measures under the Act on Prevention and Suppression of Technological Crimes took effect on 30 August 2025, the volume of fraudulent voice calls has dropped significantly. However, starting in early September, overseas fraudulent SMS rose sharply, with daily intercepted volume exceeding 1 million messages. To tackle this issue, NBTC held a special meeting focusing on control plans for A2P (Application-to-Person) SMS.
1. Classified management of domestic and cross-border SMS
Telecom operators must establish a classified management system for international and domestic SMS channels, clearly separating SMS traffic into domestic and international streams. OTP (One-Time Password) verification messages with high timeliness shall be prioritized to improve filtering efficiency and system response speed.
2. Real-name authentication and whitelist for domestic A2P senders
All enterprises or platforms sending A2P SMS within Thailand must complete registration via the KYC (Know Your Customer) process. Approved compliant senders will be added to a “whitelist”, clearly separated from overseas senders.
3. Deployment of SMS firewalls and warning labels
All network operators must deploy SMS Firewall content screening systems to automatically scan message content and block high-risk messages containing phishing links or fraudulent content in real time. For overseas SMS that pass preliminary screening, an exclamation mark (!) must be prefixed to the message content as a warning label to alert users that the message originates from abroad.
4. Mandatory SIM Box registration
Starting November 2025, all SIM Box devices must be registered with NBTC. Unregistered devices will be disconnected from telecom networks to cut off illegal channels used by fraud rings to relay scam SMS via SIM Boxes.
