What backup plan should I have for visas, immigration and long-stay planning?

Visa and entry conditions depend on nationality and purpose and can change. Use Thai government or immigration information and avoid treating social-media advice as legal authority. Keep a second transport or payment option, enough phone data and the destination written in Thai and English. Last services, app availability and road conditions can change. Avoid building an itinerary that fails completely if one bus, ferry, card or driver is unavailable. Immigration note: Entry and extension rules depend on nationality and purpose and can change. Check current Thai government or immigration requirements before relying on an older answer.