Why is the TM30 required for visa extensions in Thailand?

The TM30 form, which documents where foreigners are residing in Thailand, has become a contentious topic among expats seeking visa extensions. Some immigration offices, such as the MTT in Bangkok, do not consistently ask for this document during the visa extension process, while others, particularly in regions like Koh Samui, appear to enforce its necessity more strictly. Many community members advise bringing the TM30 just in case, as failures to register can lead to fines or complications during the visa application. Despite inconsistent enforcement, being prepared with all necessary documentation, including TM30, is recommended to avoid unnecessary risks.