For foreigners wishing to extend their stay in Thailand In the case of being family members of a foreigner holding a temporary stay visa under Section 34(7) of the Immigration Act 1979 (only parents, spouses, children, adopted children, or children of spouses), the requirements are as follows:

• They must hold a non-immigrant visa;
• Proof of relationship is required;
• In the case of a spouse, they must have a legal and de facto relationship; or
• In the case of a child, adopted child, or spouse's child requesting patronage of such child, adopted child, or spouse's child, they must not be married, must live as part of that household, and must not be over 20 years of age; or
• In case of a father or mother, he or she must be at least 50 years of age.

Required documents are as follows:

• TM.7 form;
• Copy of the applicant's passport;
• Copy of the passport of the foreigner holding a temporary stay visa; 
• Copy of relationship documents such as proof of marriage, copy of birth certificate, registration of legitimation of child, copy of house registration, registration of adoption, or other documents from public or relevant agencies.