Thailand’s Personal Data Protection Committee (PDPC) has issued a regulation establishing procedures for filing and processing data subjects’ complaints under the Personal Data Protection Act B.E. 2562 (2019) (PDPA). The Regulation Re: Complaint Filing, Rejection, Termination, Consideration, and the Period for the Consideration of the Complaint B.E. 2565 (2022) was issued in July 2022 and took effect on July 12, 2022. The PDPA entitles data subjects to file complaints against data controllers, data processors, and employees or service providers of either whose operations fail to comply with the PDPA. This article lays out the various requirements and procedures for the filing and processing of such a complaint. Complaint Submission The body designated by the PDPA to be responsible for handling complaints and imposing administrative penalties is called the “Expert Committee.” Data subjects who would like to make a complaint can submit it to the Expert Committee directly at the Office of PDPC, send it to the office by post, or submit the complaint electronically. The written or electronic complaint must use clear, plain, polite, and appropriate language, and must not give an impression of being directly or indirectly extorting or intimidating. The complaint must include at least the following information: Name, address, and telephone number or email address of the complainant (or an authorized representative), together with identification card, passport, or other official identification document (plus a power of attorney if submitted by a representative); Details and facts of the noncompliance with or violation of the PDPA; Details of resulting damages or impact; Supporting evidence (e.g., documentary evidence, physical evidence, witness statements); and Action desired of the offender. The complaint must include a statement certifying its veracity, and must be signed by the complainant or the authorized representative. Complaint Consideration When a complaint is submitted, the receiving official will