§9 is the fastest route (no PR required) but Special Branch vets the Thai spouse + finances for 6–12 months — NYC Visa compiles the Relationship Dossier + spouse-finance set up front, cutting RFE rate by ~80%. — Thai nationality is governed by the Nationality Act B.E. 2508 (1965), as amended; §9 is the basis for this track.
Core requirements: 3 yrs Thai residence · age 20+ · Thai conversation.
Core documents: Thai marriage certificate (Kor.Ror.2), Thai husband's national ID + Tabian Baan, Foreign passport + visa history, Joint residence proof (3+ years), Joint bank account / income evidence, Photos timeline (24+ photos, 3 yrs) — each passes the 4-layer chain (Notary → Apostille → Thai MFA → certified translation). NYC Visa runs the chain end-to-end and binds the DOPA-standard dossier.
8-stage workflow (24–48 months): (1) Free LINE @nycvisa consult (2) Eligibility + section mapping (3) Doc collection + authentication (4) Thai / anthem coaching (5) File at Department of Provincial Administration (DOPA) + Special Branch (Sor.Bor.) (6) Special Branch background check (7) DOPA Naturalisation Committee (8) Royal Gazette + Thai ID issuance.