Agreement is deemed to be concluded and binding when all the formal requirements for forming a contract are met i.e. offer, acceptance, intention to create a legal relationship, capacity, formality etc. In this way Thai law resembles European civil law. The general rule of contract under the Thailand Civil & Commercial Code (TCCC) is that a contract is concluded and binding where the offer is accepted and the acceptance is communicated from the offeree to the offeror.
Generally, yes, as long as the provisions are not prohibited by law or impossible or contrary to public order or good morals. One of the major risk areas are those laws that specifically restrict activities of foreigners, such as the Land Act and Foreign Business Act.
There are actually 2 different areas where the 'place' of the contract becomes important. The first is the choice of law clause, that determines the law of which nation will apply. The second is the choice of forum clause, that specifies in which nation a complaint may be filed and a legal case may be enforced in court.
The TCCC states that if the parties are of the same nationality, the laws of that country will apply. However, if the parties are not of the same nationality, the law of the country where the contract has been made will apply. In instances where a contract has been made between parties at a distance, the country where the contract is deemed to have been made is the country where notice of the acceptance reaches the seller. If such a place cannot be ascertained, the law of the country where the contract is to be performed shall govern.
Common contracts include sale and purchase of property, real estate, shareholder agreements, trust agreements, employment, hotel and property management, construction, loan, guarantees, joint ventures, franchising, licensing and distributorship.