Koh Samui is a small island with a long rental season and a lot of long-stay renters. That shapes the agreement you need: most trouble here comes from vehicles leaving on the ferry, monthly renters who change their plans, and the weeks of heavy rain at the end of the year.

This free agreement is in Thai beside English and follows the national standard contract for car and motorbike rental. The builder on this page is set to Thailand. Add your details and download it as Word or PDF.

The ferry and the permitted area

Two operators carry vehicles between Samui and Donsak on the mainland: Raja Ferry to Lipa Noi and Seatran to Nathon, roughly 90 minutes each way. A booking site lists car fares of roughly ฿800–1,200 and motorbike fares of ฿200–300 on top of the passenger ticket (Thailand Boat Tickets); check the operators' current prices.

Once a car is on the mainland, it is a long way from your shop if something goes wrong. Write "Koh Samui only" in the permitted area. The agreement then says that taking the vehicle on a ferry, to another island or further needs your written permission first, that the renter pays the ferry fees, delays and any recovery costs, and that insurance doesn't cover the vehicle outside the permitted area unless the insurer confirms it in writing. If you do allow mainland trips, set a mileage allowance per month.

Monthly rentals to long-stay renters

If you rent by the month to people living on the island for a season or longer, use the agreement's monthly mode: rent is paid in advance on the same day each month, and a payment more than 3 days late lets you end the rental and collect the vehicle.

The 2025 rules protect the renter on the way out. If they leave early, they give notice (our agreement uses 7 days for monthly rentals) and you refund the remaining rent pro rata. You can't end a monthly rental early unless the renter breaches it, but you don't have to renew it. Our guide to running a monthly rental business covers pricing and deposits for long rentals.

Rain, floods and force majeure

The island's ring road, Route 4169, is about 51 km, and local riders note that low inland and south-west roads flood in the wet season, roughly October to December (Byklo). Koh Samui has been declared a disaster area after floods more than once, for example in 2017, when the Chaweng reservoir overflowed, and in December 2024.

The agreement's force majeure clause names floods, storms and ferry cancellations: neither side is blamed for delays they cause, and rent for days the vehicle couldn't be used is agreed fairly. It doesn't have a separate flood-damage clause. The renter isn't liable for damage from proper use, so if you want to forbid riding through standing water, write it in the special conditions box, and check what your insurance says about flood damage. Remember that a car off the road for more than a day after an accident or for repairs means providing a replacement vehicle.

Green plates and the Surat Thani land transport office

Koh Samui is in Surat Thani province, and rental cars must be rented out from the area where they are registered. The Surat Thani land transport office has a Koh Samui branch at Lipa Noi (address and phone); ask them, or the provincial office in town, whether green-plate (รย.11) work can be handled on the island. The car version of the agreement asks you to confirm the rental-car registration and its insurance. Read green, yellow or white plate for the details.

Passports, deposits and fines

The agreement says you won't keep an original passport, refunds the deposit on the day of return when there's no damage, and lets you pass a posted traffic fine to the renter at the amount you actually paid. That matters for monthly renters too: a camera ticket can arrive after they've left the island.

Operators elsewhere in Thailand can use the main free bilingual rental agreement.

Let RoveHQ do the paperwork

RoveHQ fills in this agreement from each booking automatically, including monthly renewals. The renter signs it on their phone, and their passport and licence details are read from a photo, so a long-stay renter is set up in a few minutes. Start free with RoveHQ.