Use of Surname by Illegitimate Children

Foreign Service Circular No. 32-98 provides that illegitimate children shall use the surname of their mother only. Middle name is unimportant and its omission has no legal effect. However, illegitimate children may use the surname of the father if there has been an acknowledgment or recognition on the part of the father.

The requirements for the use of the surname of the father are as follows:

1. Affidavit of Recognition on the part of the father duly notarized;
2. Passport application form duly accomplished; and,
3. Payment of processing fee (THB1,125.00).