Where the law stipulates that an agreement must have writing evidnce abd be signed by the liable party in the contract. This includes lease of immovable property for a period of not over 3 years ; agreement to sell/purchase immovable property or some types of movable property ; sales contract of other movables worth over 500 Baht ; loan agreement for over 50 Baht , and surety contracts . A contract with writig evidence means an agreement made in writing , regardless of wheter it is a document or not . When the borrower sigs a piece of paper saying that he owes someone 50 Baht , the paper becomes writing evidence and the load cobtract is legally complete . Without such writing evidence , the load contract is not enforceable in a Court of Law .