The Thai Labour Law requires both Thai and foreign employers who employ a total of ten or more employees to arrange for their work rules and regulations in Thai to be announced in the work place within 15 days from the day they started employing 10 or more employees and send a copy of the work rules and regulations to the Labour Protection Office who oversees the area where the place of business is located within 7 days from the date of their announcement. Failure to do so may result in a fine of not more than Baht 20,000. For more information about what must be contained in the work rules, please see https://thailawyers.com/employers-in-thailand-with-10-or-more-employees-things-you-have-to-do/
Moreover, if later there is an amendment to the work rules and regulations, the employer shall announce the amended work rules and regulations to the employees and send a copy of the new rules and the old ones to the Labour Protection Area Office where you submitted the original ones within 7 days from the date of their announcement.