Thailand travel checklist: what to do before you go

This is the window where the expensive, hard-to-fix items get settled: passport, entry permission, insurance and the long-haul flight. Everything after this is cheaper to change.

Check your passport first. Most Thai entry exemptions require validity of about six months beyond your arrival date and at least one blank page; if you are close to that line, renew now, because renewals can take weeks. Then confirm which entry route applies to your passport: many nationalities enter visa-exempt for 30 or 60 days, others need an e-visa in advance, and the list is revised often. Use your own government's travel advice and the Thai immigration or e-visa site as the two sources that matter.

With the flight locked, the trip becomes a sequence of nights. A first trip that works is usually 3–4 nights in Bangkok as the air hub, then 4–6 more in one region: north to Chiang Mai, or south to the Andaman or Gulf islands. Trying to cover all three in ten days is the classic failure.

Book internal transport and the first nights now. Domestic flights and overnight trains between Bangkok and Chiang Mai or the south fill up in the high season (roughly Nov–Feb), and island ferries sell out around holidays. Reserve your first two nights in Bangkok and your first nights at the beach or in the mountains; leave the middle loose if you like flexibility. Check the season against your coast: the Andaman side (Phuket, Krabi, Koh Lanta) is driest Nov–Apr, the Gulf side (Samui, Phangan, Koh Tao) Feb–Sep.

Now the small things: money, phone, copies and the bag. Carry a mix of cash and cards. Baht comes in notes from ฿20 to ฿1,000; cards are fine in Bangkok, Chiang Mai and Phuket Town, but islands and small towns still run on cash, and ATMs charge a withdrawal fee per transaction, so take out larger amounts less often.

Photograph your passport, insurance policy and bookings, and keep a copy offline as well as in email. Sort your phone: an eSIM or a local SIM at the airport is cheap and gives you maps and ride-hailing. Pack for heat plus one warm layer for air-conditioned buses and mountain nights, and remember the plug types: A, B, C and O at 220 V 50 Hz, so a universal adapter covers it.

Keep the documents you will be asked for in one place: passport, boarding pass, proof of onward travel if you have it, and your first night's address in Thailand. Immigration may ask where you are staying, so have the booking name and address on screen, not buried in email.

On arrival, get a SIM or connect your eSIM before you leave the airport, take out cash from a bank ATM rather than a currency booth, and use the official taxi queue or a ride-hailing app rather than an unmarked car. Save the emergency numbers: 191 police, 1669 ambulance, 1155 tourist police. Then stop planning and eat something.

Two documents decide whether you board: a passport with enough validity and the right entry permission for your nationality. Exemption lengths and e-visa rules for Thailand are revised regularly, so treat any number you read as a starting point and confirm it with your own government's travel advice plus the Thai immigration or e-visa site before you pay for flights.

Keep digital and paper copies of the passport photo page, your insurance policy number and your bookings. If you plan to drive or ride a scooter, you need your home licence plus an International Driving Permit; without both, insurance can refuse a claim.

Thailand runs on baht (THB, ฿), with notes from ฿20 to ฿1,000. Cards work in hotels, malls and city restaurants; islands, markets, buses and small guesthouses are cash. ATMs charge a flat fee per withdrawal, so take out more, less often, and use bank ATMs attached to a branch.

Tipping is not required. Rounding up a bill, or leaving something for a massage therapist or guide, is the local habit rather than a rule. Carry a few small notes for songthaews, ferries and street food, and keep a card as backup rather than your only plan.

Get your routine vaccines up to date and check route-specific advice for Thailand well before you fly, since some courses need weeks. Dengue and other mosquito-borne illness is present in much of the country, so pack repellent and cover up at dusk. Tap water is not for drinking; sealed bottled water and refill stations are everywhere.

Travel insurance with medical and evacuation cover is the item that turns a bad week into a recoverable one; treatment and evacuation can be costly without it. Carry enough of any prescription medicine for the whole trip in original packaging, with a copy of the prescription, and check whether your medication is restricted in Thailand before you travel.

Pack for heat and humidity, with one warm layer for air-conditioned buses, trains and mountain nights. Thailand uses plug types A, B, C and O at 220 V 50 Hz, so a universal adapter covers everything. Temples require covered shoulders and knees, so bring something light to throw on.

Rain gear matters more than you think: the Andaman coast is wettest roughly May–Oct and the Gulf coast roughly Oct–Dec, so a compact umbrella or shell earns its space. Leave room for what you buy there; light clothing is cheap and everywhere.