When you are unable to be physically present to execute an ownership transfer at the Land Department, you may ask someone to represent you and do it on your behalf. To make this possible and valid according to the Law, it must be done through a Thai Official Power of Attorney.
A Thai Official Power of Attorney is the means through which one person (the Principal) empowers another person (the Agent) to act on the behalf of the Principal, and make such act have the same legal effect as if it was done by the Principal himself/herself.