Letter of approval from the Ministry of Labor. To obtain this letter, the applicant’s prospective employer in Thailand is required to submit Form WP3 at the Office of Foreign Workers Administration, Department of Employment, Ministry of Labor Tel. 02-245-2745, or at the Provincial Employment Office in his or her respective province. More information is available at Department of Employment or www.doe.go.th (only if applicant can’t submit a copy of a previous Work Permit.)