The Land Code of Thailand along with the Foreign Business Act (FBA) does not prohibit foreign control (voting and management) of a Thai majority owned company that owns land in Thailand.
Given the above, it is of paramount importance that a proper legal structure is adopted to retain effective control over a Thai majority owned company whilst at the same time avoiding anti-agency and anti-nominee provisions.
A number of means can be used to ensure that the foreign minority shareholders have effective management and financial control of the company.
These include but are not limited to creating different classes of shares along with different voting and director appointment rights.
As an additional safeguard you may set up a company to control the freehold land which you as an individual then lease from the company you control. Further, you may also have the company register a mortgage over the land in your favor.
If you choose to purchase your property freehold you should consult with professionals who will adopt the proper legal structure to protect your interests and who are able to explain the same to you in detail, in your own language or at least in a language that you understand well.
You should also be aware that there are legal responsibilities and tax implications with respect to the owning and running of a Thai company.
If choosing the Freehold method of ownership and control you should appraise yourself of these costs, responsibilities and implications by consulting the professionals in this field such as the Pensit and Laws Group.