A Thai birth certificate is NOT automatically issued when both parents are foreign and are not legally resident, i,e have PR status in Thailand.
Jus Soli is not an inherent right here.
Thailand operated a system of pure jus soli prior to 1972. Due to illegal immigration from Burma, the Nationality Act was amended to require that both parents be legally resident and domiciled in Thailand for at least five years for their child to be granted Thai citizenship at birth.[83][84] Furthermore, someone who has Thai citizenship by sole virtue of jus soli may be stripped of Thai citizenship under various conditions (such as living abroad), which does not apply to people who have Thai citizenship by virtue of jus sanguinis.
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