We quote this Thailand Property FAQ :
Usually when you buy a new property in Thailand especially a Freehold Condominium, it is preferred that you pay directly from your account in your home country directly to the developers account as to obtain a Freehold title you will need to show the local land office that the money used to buy the property has originated from outside of Thailand. You will have to provide a Foreign Transaction Form (FTF) which is issued by the developers/Thai bank upon arriving in Thailand in the case that the transferred amount is 20,000 USD or over, these FTFs need to be kept and presented at the land office upon transfer of the title deed. It is very easy to open a bank account in Thailand (however some agencies ask for valid work permit) and it is possible to pay for a property, even a Freehold property, from a Thai bank account after transferring money from abroad to your Thai bank account.
For leased property you are not required to provide such documentation.
