Should I book accommodation in advance?

Only book your first 3-4 nights in Bangkok. The rest can be booked 1-2 days ahead using Agoda, Booking.com, or by walking in. Exception: if traveling December-February, book popular islands and Ha Long Bay tours 3-5 days ahead.

Is it safe to travel overland between all three countries?

Yes, the overland route is well-established and safe. Millions do it annually. Use reputable bus companies, avoid overnight buses when possible, and keep valuables with you. Border crossings are straightforward but can involve pushy touts - walk past them to official counters.

What if I get sick and need to extend my trip?

All three countries have visa extension options. Thailand allows 30-day extensions for $60 at immigration offices. Cambodia offers extensions up to one year. Vietnam's e-visa cannot be extended, but you can exit and re-enter with a new visa if needed.

How much should I budget for activities and tours?

Angkor Wat pass: $37/day or $62/3-day. Ha Long Bay tours: $50-120 for 2-3 days. Cooking classes: $20-35. Motorbike rentals: $5-10/day. Scuba diving: $25-40/dive. Temple visits: $2-10 each. Most activities are affordable - budget $100-200 total for major experiences.

How to Plan a 3-Month Thailand-Cambodia-Vietnam Route

Start in Thailand (6-7 weeks), move to Cambodia (2-3 weeks), then finish in Vietnam (4-5 weeks). Enter Thailand visa-free, get Cambodia visa on arrival, and arrange Vietnam e-visa in advance. Budget $35-50 per day total and follow the overland route: Bangkok → Chiang Mai → border crossing to Siem Reap → Phnom Penh → Ho Chi Minh City → Hoi An → Hanoi.

Map your route and timing. Plan Thailand first (6-7 weeks), Cambodia middle (2-3 weeks), Vietnam last (4-5 weeks). This follows the natural overland flow and weather patterns. Book your entry flight to Bangkok and exit flight from Hanoi. The classic route is Bangkok → Chiang Mai → Siem Reap → Phnom Penh → Ho Chi Minh City → Hoi An → Da Nang → Hanoi.
Handle visas in the right order. Most passport holders get 30-60 days visa-free in Thailand (check your specific nationality). Get your Cambodia visa on arrival at any border crossing ($30 for 30 days). Apply for your Vietnam e-visa online before you leave home or while in Thailand - processing takes 3-5 business days and costs $25. Never wait until Cambodia to apply for Vietnam as internet can be unreliable.
Book only your first week. Book 3-4 nights in Bangkok to start, then leave everything else flexible. You'll want to adjust timing based on weather, who you meet, and what you discover. The only exception is if you're traveling during peak season (December-February) when some popular spots like Railay Beach or Ha Long Bay tours can fill up.
Plan your border crossings. Thailand to Cambodia: Use Poipet border crossing if going to Siem Reap, or Koh Kong if heading to coastal Cambodia. Cambodia to Vietnam: Cross at Bavet-Moc Bai for Ho Chi Minh City or Kaam Samnor-Vinh Xuong for the Mekong Delta. Each crossing takes 1-3 hours. Bring exact change in USD for Cambodia visa fees.
Set up your money situation. Get a no-foreign-fee debit card before you leave. Notify your bank of travel dates. Cambodia uses USD alongside riel - bring clean, newer USD bills as banks reject damaged ones. Thailand and Vietnam use ATMs everywhere. Budget for ATM fees of $2-5 per withdrawal and withdraw larger amounts less frequently.
Pack for three climates. You'll hit hot and humid (Thailand south), dry and dusty (Cambodia), and potentially cool mountains (Vietnam north). Pack one warm layer for northern Vietnam and air-conditioned buses. Bring reef-safe sunscreen as it's expensive and hard to find. Pack light - you can buy cheap clothes everywhere and ship things home from Vietnam for $15-30.

Should I book accommodation in advance?: Only book your first 3-4 nights in Bangkok. The rest can be booked 1-2 days ahead using Agoda, Booking.com, or by walking in. Exception: if traveling December-February, book popular islands and Ha Long Bay tours 3-5 days ahead.
Is it safe to travel overland between all three countries?: Yes, the overland route is well-established and safe. Millions do it annually. Use reputable bus companies, avoid overnight buses when possible, and keep valuables with you. Border crossings are straightforward but can involve pushy touts - walk past them to official counters.
What if I get sick and need to extend my trip?: All three countries have visa extension options. Thailand allows 30-day extensions for $60 at immigration offices. Cambodia offers extensions up to one year. Vietnam's e-visa cannot be extended, but you can exit and re-enter with a new visa if needed.
How much should I budget for activities and tours?: Angkor Wat pass: $37/day or $62/3-day. Ha Long Bay tours: $50-120 for 2-3 days. Cooking classes: $20-35. Motorbike rentals: $5-10/day. Scuba diving: $25-40/dive. Temple visits: $2-10 each. Most activities are affordable - budget $100-200 total for major experiences.