Modified 12th June 2025
Legal Guidelines for Tourists Travelling to Koh Tao
SUMMARY –
- Thailand now requires all foreign visitors to complete the Thailand Digital Arrival Card (TDAC) before arrival.
- Recreational cannabis has been illegal again since June 2025, with medical use allowed only with a fresh prescription. Hard drugs and vaping carry severe penalties, including imprisonment.
- The legal drinking age is 20, with alcohol sales allowed only during designated hours. Drinking is banned in temples, public transport areas, petrol stations, parks, and government buildings.
Koh Tao, often called ‘Turtle Island,’ is a popular getaway famous for its diving and snorkeling spots.
However, the relaxed island vibe, beautiful scenery, and lively nightlife can make it easy to forget that Thailand operates under an exceptionally strict legal framework. And violating these rules can lead to serious legal problems.
Adding to that, recent government updates have strengthened enforcement across the country, especially in areas such as immigration, tourist conduct, and marine conservation.
Because of these stricter measures, understanding the rules before you arrive is more important than ever.
This detailed guide explains all the essential legal guidelines so that you can stay safe, lawful, and respectful without getting into any legal trouble.
Important Laws to Follow in Koh Tao to Stay Out of Any Trouble
In Koh Tao, Thailand, even minor violations can result in fines, penalties, or legal complications that can easily ruin your trip. Taking a few minutes to familiarise yourself with the rules will help you avoid unnecessary trouble and ensure a smooth, stress-free stay.
Below are the most important laws every visitor should keep in mind.
1. Entry, Visa & Immigration Rules
All immigration rules of Thailand, such as visa on arrival, visa exemptions, overstays, extensions, apply equally on Koh Tao.
On May 1, 2025, Thailand has digitised its arrival process. All foreign visitors are now required to complete the Thailand Digital Arrival Card (TDAC) online before entering the country.
NOTE: Not submitting this form in advance can lead to long delays at immigration or, in some cases, denied entry.
Visa Exemption (Most Common for Many Nationalities) – Travellers from many countries can enter Thailand under the Visa Exemption Scheme. This means some nationalists can enter Thailand without a visa. This typically allows a stay of up to 60 days.
Important Note: According to the Thai Government, its 60-day rule may go back to 30 days from 2026 onwards, so it’s highly recommended that you check the official tourist guidelines before travelling to Koh Tao.
Stay Limits – The initial stay period can also be extended once for an additional 30 days at the Thai Immigration Office.
Visa on Arrival (VOA) – This is applicable for nationalities who are not eligible for the Visa Exemption but are allowed for VOA. You get the visa when you reach Thailand (airport or land border).
- The stay allowed is 15 days only.
- This is only for short visits.
Example – You land in Bangkok, fill out a small form, pay the fee, and get 15 days.
Thailand Tourist Visa – If you’re not eligible for Visa Exemption or Visa on Arrival, or you want a longer stay, you need to apply for a Tourist Visa before you travel (at a Thai Embassy/Consulate).
These are of two types –
- Single-Entry Tourist Visa (Most common)
- Valid for one entry.
- Allows you to stay for 60 days. You can extend it once for 30 days.
Important Note – If you leave Thailand during the 60 days without a re-entry permit, then the visa gets cancelled.
- Multiple Entry Tourist Visa (Harder to Get)
- Valid for 6 months.
- You can enter Thailand as many times as you want during these 6 months.
- Each entry gives you 60 days, with an option to extend 30 days.
- Usually requires stronger financial proof and a reason for multiple entries.
The Risk of Overstaying – In the eyes of the law, overstaying the duration permitted by your visa or entry stamp is a criminal offence. Penalties are applicable quickly, depending on how long you overstay, irrespective of the fact that you voluntarily surrender to authorities or are arrested.
| Duration of Overstay | Voluntary Surrender Fine | Voluntary Surrender Ban | Arrested Ban |
|---|---|---|---|
| Less than 90 days | 500 THB per day (max 20,000 THB) | Allowed to leave (No ban) | Up to a 5-year ban |
| More than 1 year | 20,000 THB | 3-year ban | 10-year ban |
| More than 5 years | 20,000 THB | 10-year ban | 10-year ban |
Advice – Always carry valid travel documents, including copies of your passport and entry stamp. Also, check your visa validity before taking any dive or boat trips around Koh Tao. For more information on travelling to Koh Tao from Thailand, please refer to the guide – Cómo llegar a Koh Tao desde cualquier lugar de Tailandia.
2. Drug Laws & Controlled Substances
Thailand maintains some of the harshest drug laws globally. The rules were loosened for a while, but the government has now firmly brought them back.
Putting Back Under Criminal Law– Since June 2025, recreational cannabis has been illegal again in Thailand and is only allowed for medical use.
Important Note –
- To legally get cannabis in Thailand, you need a valid medical prescription from a licensed doctor. And, it must be issued within the last 30 days. Recreational use is not allowed. Breaking these rules can lead to criminal charges, including up to one year in jail and a fine of 20,000 baht.
- Penalties for breaking the law are applied to anyone aged under 18 years. And, the penalties for children can include detention in a juvenile and sometimes in adult prison.
Narcotics – Laws regarding hard drugs (e.g., ecstasy, cocaine, heroin)remain extremely strict. Possession, use, or trafficking is taken seriously with penalties that include severe jail sentences and even the death penalty.
Vaping – Vaping is strictly illegal. E-cigarettes, vaporisers (vapes), and refills are illegal to possess or use in Thailand and Koh Tao.
Advice for Travellers – Avoid all drug use. Don’t assume that “soft drugs” are accepted. Thai authorities enforce drug laws very strictly.
3. Alcohol & Drinking Regulations
Koh Tao is lively, but alcohol use is strictly regulated, especially for age and sale times.
Legal Drinking Age – The legal age for purchasing and consuming alcohol is 20 years old. Visitors are advised to carry their passports as ID for age verification.
Note – Even in busy tourist areas, alcohol cannot be sold or consumed in public during restricted hours. Make sure to plan safe transport after drinking and follow local rules.
Purchase/Sales Restrictions – Alcohol can be bought during these hours: 11:00–14:00, 14:00–17:00 (as part of a six-month trial starting 3 December 2025), and 17:00–24:00.
Hotels, licensed bars, and international airport terminals for departing passengers can serve alcohol outside these hours if they have special permits.
Visitors who bought and started drinking alcohol before the restricted hours can continue for up to one hour after the sales ban starts. This rule only applies to drinks purchased before the cutoff and takes effect from 3 December 2025.
Drinking or purchasing is strictly prohibited –
- Temples
- Government Offices
- Parks
- Petrol Stations
- All Public Transport Areas (including train and bus stations, piers, and airport terminals except in approved duty-free or licenced zones and on board any public vehicles).
Important Note – Violations can result in heavy fines and ID checks.
4. Respecting the Monarchy – “Lèse‑Majesté” Law
This is one of the most serious laws for visitors. The Lèse-Majesté law (Section 112) is a major crime in Thailand. The law forbids –
- Defaming the monarchy
- Insulting and threatening the King & the Queen
- Disrespecting The Heir-Apparent and The Regent
Take care not to commit offences against the monarchy even on social media.
Advice – Do not make any comments about the monarchy –
whether in person,
online,
or on social media.
Also, never damage or disrespect royal images such as currency, portraits, or statues.
5. Gambling, Cards & Prohibited Games
Gambling is illegal in Thailand, and the rules apply to both locals and tourists. This goes for many card games, too.
Note – Violation of this act may lead to –
- prosecution,
- heavy fines,
- or even imprisonment.
6. Environmental Laws, Littering & Wildlife / Marine Protection
On Koh Tao, protecting the environment is very important. Thailand has strict rules for waste management and marine conservation, especially around the popular dive sites.
Zero-Tolerance for Marine Damage – As of April 2025, it is illegal to touch marine life, move corals, or feed fish. These actions harm the ecosystem.
For example, feeding fish changes their natural behaviour and can cause algae to grow, which smothers coral.
Note – The maximum punishment for feeding fish or damaging the marine environment is a fine of up to 100,000 THB or one year imprisonment, or both.
Plastic Ban – In all National Parks, including areas surrounding Koh Tao, the use of single-use plastics such as disposable cutlery, straws, and Styrofoam is banned.
To understand why this is so important to the local community, check Marine Conservation Koh Tao: Complete Guide to Ocean Protection.
7. Dress Code, Public Decency & Cultural Respect
Thai cultural norms require respectful dress, especially when visiting sacred sites.
Rules for Visiting Temples – While on Koh Tao, you might spend most of your time in swimsuits, visiting temples or certain official sites requires modesty. At major sites like The Grand Palace (and many others), inappropriate outer garments include shorts, mini-skirts, vests, and torn jeans for both men and women.
Public Decency – Indecent behaviour like helping another person engage in sexual acts by persuading, taking, or arranging someone, whether they agree or not, can face serious punishment. This can be imprisonment for 1 to 10 years and a fine of 2000 to 20000 Baht.
Advice – Pack clothes that are appropriate for the beach and diving, but also include modest attire (long trousers, shirts with sleeves, or a sarong) for visiting temples, shops, and villages.
Practical Advice for Divers & Tourists on Koh Tao
If you plan to enjoy the water, a few basic precautions can help you avoid legal or safety problems. Being prepared lets you relax and enjoy the amazing underwater world.
Before Diving or Snorkelling – For this, follow local dive rules and practice responsible diving. Keep at least two meters away from coral reefs and use only reef-safe sunscreen, as banned sunscreens can lead to penalties up to 100,000 Baht.
Documents to Carry – Always carry copies of your passport, relevant visa pages, and, if applicable, your dive certification and contact information for your resort or dive operator.
Nightlife Awareness – Respect local norms at night. Enjoy the bars and beach parties, but be aware of the strict alcohol laws. Also, remember that theft and break-ins can happen, especially in budget guesthouses.
Important Note – Remember that foreign tourists do not get special treatment under Thai law. Not knowing the rules is not accepted as an excuse in the Thai legal system.
What to Do if Things Go Wrong – Legal or Medical Help & Resources
Even with the best intentions, emergencies can still happen. Having the right contact numbers ready can make a big difference in how quickly you get help.
If you end up in trouble, stay calm, cooperate, and get professional assistance right away. Don’t try to handle legal issues on your own.
| Emergency Contact Service | Phone Number | Notes |
|---|---|---|
| Tourist Police | 1155 (24 hours) | Recommended first contact. Operators speak English, and the Koh Tao Tourist Police also have Western volunteers who can help with translation and resolving disputes. |
| General Police/Emergency | 191 | For general crime reporting or immediate police presence. |
| Fire Department | 199 | For fire emergencies. |
Insurance – Always get good travel insurance that covers emergency medical costs. If you plan to dive, make sure your policy includes dive insurance, as it’s important for treatments like decompression sickness.
Embassy Contact – If you commit a serious violation (e.g., getting arrested for a severe offense), immediately contact your country’s embassy or consulate. They can provide a list of local, reputable legal assistance providers.
Conclusión
Travelling to Koh Tao promises an unforgettable experience with world-class diving, warm tropical weather, and welcoming local culture. But enjoying this dream trip fully depends on respecting local laws and cultural expectations.
There are five key areas every visitor should pay close attention to –
- strict drug laws
- regulated alcohol rules
- the sensitive Lèse-Majesté law
- strict environmental protection laws
- and local customs and etiquette
By following the local rules and choosing a reliable dive centre like LA BOMBONA DIVING, you can enjoy your trip safely, responsibly, and without breaking any marine or environmental laws. This will help you in preserving the incredible environment and culture that make Koh Tao so unique.
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