Foreigners staying in Thailand who are providing patronage to a Thai citizen or are under the patronage of a Thai citizen (husband-wife, parents or unmarried children under 20 years of age) must submit an application to the Immigration Office for an extension of their visa and apply for residence. Overstaying is considered an offense under the law. The application requirements are as follows: 

 1. TM.9 form;

 2. Medical certificate from a public hospital (not older than 3 months);

 3. Letter certifying that the applicant has no criminal record from the country where he or she is domiciled;

 4. Copy of a family certificate, such as a marriage certificate not older than 3 months, a birth certificate, a copy of the house registration;

 5. Copy of residence certificate, alien certificate, passport and a copy of the house registration in Thailand, every page with a list of residents in Thailand, together with the original copies; 

 6. Copy of the document showing the applicant's academic qualifications;

 7. Previous employment certificate from the Office of Foreign Workers Administration, Department of Employment, and copies of all work permits, every book, every page;

 8. Salary certification letter from the company where the patron has worked for the past 2 years;

 9. Copy of the personal income tax return (PND.91 or PND.90) of the applicant with withholding tax under section 50 bis for 3 years prior to the year of application submission;

 10. Copy of the withholding tax return (PND.1) from the beginning of the year until the month prior to the application submission;

 11. Certificate of registration of the juristic person where the patron works;

 12. Copy of the certificate of registration of the juristic person where the patron has worked for 3 years prior to the application submission;

 13. List of shareholders (copied version from the Ministry of Commerce and not more than 3 months old from the date of application submission) and if the patron holds shares of 5 million baht or more, a list of shareholders for the past 3 years must be presented;

 14. Copy of VAT registration or specific business tax, such as PP.01, PP.09, and PP.20 forms;

 15. Copy of financial statements (balance sheet, profit and loss statement) together with PND.50 form prior to the year of application submission, which is certified by the officials of the Revenue Department with a copy of the receipt (in the case of a government agency or a state enterprise, this document is not required);

 16. Bank letter confirming the export of goods in the past 3 years prior to the year of application submission (only export businesses);
 17. Certificate of bringing in tourists for the past 3 years prior to the year of application submission from agencies related to tourism (tourist business only);

 18. Any juristic person receiving investment promotion must provide a copy of the promotion certificate or documents showing that it has been promoted;

 19. Map showing place of residence and workplace; 

 20. Copy of passport showing permission to stay for at least 3 years (every book, every page);

 21. Personal data form and photos of the foreigner outside the workplace (alone), inside the workplace with other employees, outside the factory (alone), inside the factory with other workers, machines and products (if any), photos of the foreigner outside his or her residence, inside the residence with his or her family ( if any), totaling 10 photos, postcard size, each photo mounted on A4 size corporate head paper with captions under each photo;

 22. In the case of a child being under patronage of a father or mother or a child being a patron of a father or mother, proof of a DNA test from a government hospital showing the relationship between the child and the father or mother must also be presented. 

Information as of 8 February 2023

Source: Immigration Office

Tel. 1178 or +66 2572 8500