Due diligence before buying on Koh Phangan: the complete checklist

Due diligence is the stage between signing a reservation and signing the real contracts. For a purchase on Koh Phangan it covers five areas: the title deed and Land Office record, the seller's identity and authority, encumbrances and registered claims, physical boundaries and road access, and buildability under the zoning rules. Shortcut any of these and you're either buying a risk or trusting a story.

Start at the Land Office

The back of any Chanote or Nor Sor 3 Gor deed is the most important document in the transaction. It records every ownership transfer, every registered mortgage, lease, usufruct, servitude and court order — all dated and stamped by the Land Department. Bring the deed (or its number) to the Koh Phangan Land Office and compare it against the official record copy. This is not a formality — it is the check.

1. Title class and condition

• Aim for Chanote (full GPS-surveyed ownership deed) or Nor Sor 3 Gor (usable with care). Por Bor Tor 5 is a tax receipt, not a title — it cannot be legally owned or transferred. Sor Por Kor land is reserved for Thai farmers. See Land titles on Koh Phangan.
• Hold the deed against light to verify the Garuda watermark and the Land Department officer's signature with red official stamp.
• Check that the deed number, plot number and province match exactly what was represented by the seller.
• Confirm the title has not been split, subdivided or altered since the last transfer.

2. Seller identity and authority

• The seller's name on the deed must match their Thai national ID exactly — no exceptions.
• If the seller is a company, verify its registration at the Department of Business Development: that it is active, tax-compliant and not under investigation. Obtain a board resolution authorising the sale, signed by directors listed in the registration.
• Post-2025: if a company seller is involved, also check whether it sits on a high-density registered address — a classic indicator of nominee structures. See Leasehold vs freehold.
• For a leasehold transfer, confirm the original lessee has the right to assign under the lease contract — if there is no assignment clause, the transfer may be blocked.

3. Encumbrances and registered claims

• Read the back of the deed for mortgages, leases, usufructs and servitudes. These do not disappear on a sale unless expressly released before or at transfer.
• Request a formal encumbrance search (สารบัญจดทะเบียน) at the Land Office to get the complete current picture.
• Check for court seizure orders or injunctions — these are also registered on the deed and would freeze any transfer.
• For a leasehold purchase specifically: confirm the lease is registered on the back of the deed with the correct term and dates. A lease over three years that is not registered there is only enforceable for three years, regardless of what the contract says.

4. Boundaries, survey and road access

• Walk the entire plot with a licensed surveyor and confirm the concrete boundary markers (ลูกบาน) are present, numbered and match the deed's cadastral plan.
• Commission a GPS boundary survey if any marker is missing, displaced or the plot shares a contested boundary with a neighbour.
• Verify registered road access — a right of way to the public road that is registered on the deed, not merely assumed or verbal. A landlocked plot with only verbal access is one of the most common traps on the island.
• Match the deed's stated area (in rai/ngan/talang wah) against the physical survey. Discrepancies need resolution before exchange.

5. Buildability and the 2025 zoning rules

A clean title tells you what you own — it does not tell you what you're allowed to build. Under the 2025 environmental protection rules, Koh Phangan has seven construction zones with different height limits, setbacks and footprint maximums. Hillside (80 m+ elevation) and beachfront plots carry the tightest restrictions. Check the plot's elevation and distance from the shore against the rules before you commit. A plot you can't build the intended villa on is not the asset you priced it as. See Building zones on Koh Phangan.

6. Utilities, permits and the physical plot

• Confirm the source and reliability of water supply — government main, private well or shared tank are all common on Phangan, and reliability varies significantly.
• Verify electricity meter registration with the Provincial Electricity Authority.
• If a building already exists on the plot, check that the construction permit (Por Ror 1) exists and that the structure matches the approved plans. Unauthorised additions are common and become the buyer's problem at transfer.
• Ask neighbours about flooding, drainage and the dry-season road condition — photos don't capture these.

Independent legal due diligence is the step that separates a sound purchase from one that transfers someone else's problem to you. Use a lawyer who is not also acting for the seller or developer — that independence is the point. For where due diligence fits into the full purchase timeline, see How to buy property on Koh Phangan step by step.