The process of registering a Branch Office in Thailand is slightly more complex than registering a limited company due to the lengthy duration and cost of incorporation, but several multinational companies may choose to proceed with this option. It should be noted that since the branch is a foreign entity, its activities must not fall under the Foreign Business Act’s lists of prohibited activities. The minimum capital required for establishment is at 3 million THB, and there is also a 3 million THB investment required for every business activity which the Branch Office will operate in Thailand. Once registered, the Branch Office will also receive a Foreign Business License to operate its business in Thailand.
You will never have to touch a legal form (apart from signing it).