Thailand, planned properly: connectivity, cover, and the islands that close.

Thailand is the one destination on this list where buying locally is not a compromise. AIS, TrueMove H and the operators consolidated around them run competitive tourist data plans, sold at staffed counters in the arrivals halls at Suvarnabhumi, Don Mueang and Phuket, and registration against a passport takes a few minutes. Data allowances on those tourist plans are generous, and coverage across the mainland is genuinely good.

So the argument for an eSIM here is narrower and more honest than elsewhere: it is about the first hour and about not carrying a second piece of plastic. You land, the transfer app works, the hotel confirmation loads, and you are through the terminal while the SIM counter queue is still forming. For a short trip, or a trip where you are connecting straight to a domestic flight to an island, that convenience is the whole value. For a long stay on the mainland, the local plan usually wins on allowance.

Roaming on an Indian plan is the third route. Thailand is common enough in Indian carriers' international packs that it is worth checking what yours actually costs before dismissing it, particularly for a short trip where the daily rate barely accumulates.

Coverage caveats are geographic and predictable. Bangkok, Chiang Mai, Phuket, Krabi and the mainland corridors are well served. Signal thins on the ferries, on Koh Phi Phi's quieter beaches, in the Similan and Surin island groups, and in the far north's hill country. If your plan involves ferries and longtails, keep the maps offline and the ticket confirmations screenshotted.

The medical reality in Thailand is specific and worth understanding before you choose a policy. Private hospitals in Bangkok, Phuket and Chiang Mai are genuinely excellent and are organised around treating international patients — and they typically want either a direct-billing arrangement with your insurer or a payment guarantee before major treatment. If your policy is a reimburse-later product, that means a large charge on your card while the claim is processed. Knowing which of the two you hold, and carrying the insurer's emergency assistance number, is the practical preparation.

The exclusions cluster around exactly what people go to Thailand to do. Scooter and motorbike hire is universal in Phuket, Koh Samui and Pai, and the licence-and-helmet conditions apply the same way they do in Bali. Diving is a headline activity in the Andaman, and depth limits and certification conditions apply. Jet skis, ATVs, zip lines, rock climbing at Railay and Muay Thai training all sit in adventure-sports territory. Read the schedule, not the brochure.

There is also a public-health dimension worth planning around rather than insuring against: dengue is present, mosquito activity peaks in the wet season, and repellent plus covered evenings does more for you than any policy clause.

On whether insurance is required for entry: Thailand has at various times attached health-insurance conditions to specific visa categories, and those requirements have been introduced, modified and withdrawn. Do not generalise from a friend's experience on a different visa type. Confirm the condition that applies to your entry route with the Thai embassy or consulate and the Immigration Bureau before you travel.

Phuket airport sits at the wrong end of the island for almost every visitor. Patong, Karon, Kata and Kamala are all a substantial drive south over a hill road, and the journey is longer than the map suggests. Metered taxis, a public airport bus and pre-booked private transfers all serve it; the reason travellers pre-book here more than elsewhere is that Phuket's ground transport has long been negotiated rather than metered, and arriving with a fixed price removes an argument you cannot win at midnight.

In Bangkok, the crucial thing is to know which airport your ticket uses. Suvarnabhumi and Don Mueang are on opposite sides of a very large city, and a self-arranged connection between them — common when an international arrival meets a domestic low-cost departure — needs hours, not minutes. Suvarnabhumi has the Airport Rail Link into the city and connects to the BTS and MRT networks; Don Mueang relies on buses, trains and road.

Island onward legs deserve the same care. Ferries to Phi Phi, Koh Lanta, Koh Tao and Koh Samui run to schedules that shrink in the low season and get cancelled in bad weather. If a ferry sits between you and an international flight home, do not make it the same day.

Thailand's supply of hotels, restaurants and day tours is deep enough that most of a trip can be arranged on the ground. What cannot be arranged on the ground is entry to a national park during its closed season, or a bed anywhere during Songkran.

The right order is therefore: check the park calendar for the islands you care about, check the festival calendar against your dates, and then book everything else casually. Getting those two right does more for a Thailand trip than any amount of advance activity booking.

Thailand has in recent years operated a visa exemption for short tourist visits by Indian passport holders, which is the general position most travellers arrive under. It is also the least permanent arrangement on this list: Thailand's rules for Indian passports have moved more than most, between visa-on-arrival, temporary exemption schemes and electronic authorisation, and the exemption has been extended and revised rather than settled. The permanent-sounding advice you will find in older articles is exactly the advice most likely to be wrong, so check what applies to your dates with the Immigration Bureau before you book.

Thailand has also moved arrival formalities online, with a digital arrival card completed before travel replacing the paper form. It is free through the official government channel, and there are look-alike sites that charge for it — start from the Immigration Bureau.

Immigration can ask for proof of onward travel, accommodation and funds, and those checks are applied more often on low-cost one-way itineraries. Have the return ticket and first booking on your phone. Verify current rules before booking, and remember that permission to travel is not the same as admission.