Buying property in Koh Samui as a foreigner

Yes, but only a flat, and on Koh Samui there are almost none. A foreigner holds a Thai condominium freehold under section 19 of the Condominium Act, inside a 49% foreign quota per registered building. One agency counted five Samui developments with good units available in January 2026, and two of those were new build. Land stays Thai.

Current at 9 September 2026. Dollars at THB 32.9 to US$1, the rate of 8 September 2026.

The foreign-freehold stock here is about two buildings deep

Supply matters more than the rule. That count of five comes from a single agency (charlesdel.com, 17 January 2026), and nobody publishes a competing number. CHECK The right to own in your own name is real. There is almost nothing to use it on. Everything else you buy after moving to Koh Samui sits on land you lease.

The second problem is the hillside, where the best plots are. The rule deciding whether a slope can be built does not agree with itself. One family, from charlesdel.com, gives it in degrees. From 35 to 50 degrees, only a single detached house applies, capped at 80 m² on at least 480 m² of land, with 75% left unbuilt. Above 50 degrees, nothing may be built. The other family, from lexbangkok.com and ancra.my, gives it as gradient. At 35% or more, only one detached house applies, capped at 6 metres, with 70% of the land left permeable above 100 talang wah. Cut-and-fill is capped at 2 metres. Above 50% gradient, nothing may be built either. Thirty-five degrees is roughly a 70% gradient. Only the 50 ceiling is shared; every other number differs by family (charlesdel.com; lexbangkok.com, 2025). CHECK

Both readings sit under one MNRE notification (B.E. 2568), effective 22 May 2025 to 21 May 2030. It also caps every building at 12 metres and three storeys island-wide. Construction is barred in the first 10 metres from the shoreline, then limited to a single storey up to 6 metres out to 50 metres. Have a Thai lawyer read it against your plot, not an agency page and not this one.

You can own the flat, never the ground under it

A lease running more than three years must be registered at the Land Office to bind a buyer at all, under Civil and Commercial Code section 538. The money for a condominium has to arrive from abroad, in foreign currency, in your name. Your bank issues a Foreign Exchange Transaction form at US$50,000 and above, and the Land Office will not register without it. That makes opening a Thai bank account an early step. The Samui guide names the two developments where that quota is still open, with entry prices for both.

Closing costs run 2.5% to 6.3%, and foreigners pay the full transfer fee

Rates are Thailand-wide (thethaiger.com and thephuketnews.com legal guides, July to September 2026).

Work it on a real number. The median Samui condominium one-bedroom asks THB 3.5 million ($106,400) on a 40–70 m² unit, from the 2026 market report. The transfer fee alone is THB 70,000 ($2,128). All in, budget THB 87,500 to 220,500 ($2,660–6,702) on top of the price. That puts the total at THB 3,587,500 to 3,720,500 ($109,042–113,085), plus about THB 700 ($21) a year in tax. The 0.01% fee running to 30 June 2027 is for Thai buyers only.

Leasehold runs the same sum on a bigger base. The median Samui villa asks THB 14.7 million ($446,800). A 30-year lease at that premium registers at 1.1%, or THB 161,700 ($4,915).

Three traps here have cost people the whole purchase

The 30+30+30 lease is dead. A March 2025 Supreme Court ruling held that pre-agreed automatic renewals beyond the statutory 30 years are void. The promise is personal. It binds neither the land nor a future owner, and no court will enforce it. The basis is section 540 of the Civil and Commercial Code. Anything you pay for years 31 to 90 is expenditure, not an asset. The docket carries Buddhist year 2566, which is 2023, while the reported date is March 2025. CHECK

A nominee company is not a structure, it is an offence. On 15 August 2026 more than 300 officials landed on the island. They opened 60 cases against 88 suspects, 26 Thai and 62 foreign, and arrested 14 foreigners, including one French national. Fifty-nine companies were found holding 37 plots and buildings, worth an estimated THB 1.2 billion ($36.5 million) (nationthailand.com, 15 August 2026). More than 7,000 companies are under the same nominee review nationwide. Agencies now say openly that resale villas held in Thai companies are hard to transact.

A stamped building permit is not proof of legality here. A municipal officer allegedly sold forged Or.1 permits at around THB 100,000 ($3,040) each. Detected in October 2025 during routine inspections, it became public on 21 March 2026. Initial checks flagged nearly ten forged permits. The wider Samui Model task force separately found more than 100 questionable ones island-wide, in a different audit of the same permit records (fosrlaw.com, 26 March 2026). An unlawful building faces demolition under section 42 of the Building Control Act. The Samui Model task force had 98 cases open and 21 demolition orders by January 2026, and two villas were demolished in August 2024. Verify any permit against municipal records, never the seller's file.

Supply is rising faster than demand, and nightly rates are falling

The primary market is THB 30.3 billion ($921 million) across 2,882 units in 117 projects (samuipropertygroup.com market report, 2026). Condominiums are 52% of those units, at a median THB 88,500 per m² ($2,690). Villas are 48%, at THB 60,600 per m² ($1,842), and the median villa asks THB 14.7 million ($446,800). A three- to four-bedroom sea-view villa starts near THB 15 million ($455,900) here, against THB 30 million-plus ($911,900) on Phuket.

Now the direction, which agents skip. Luxury launches in the first half of 2025 came to THB 14.8 billion ($450 million), across 52 projects and 597 units. That was up 63.56% on the second half of 2024, the most active year for villa launches in 15 years. Villa rental supply rose 34% year on year, to 3,055 villas by January 2025. The island's average nightly rate fell 11% to THB 13,012 ($395) in Q1 2025. Occupancy held at 71.5%, so supply, not weaker demand, moved the rate. More villas are chasing the same guests.

Appreciation is forecast at 5% to 7% for 2026 island-wide, by people who sell villas (samuipropertygroup.com, 2026). The Gold Triangle of Chaweng Noi, Bophut and Choeng Mon is forecast higher, at 7% to 9% (conradproperties.asia, December 2025). Two other numbers do not stand up. No vacancy or unsold-inventory series is published for Koh Samui, so nobody can tell you how much stock is sitting. CHECK And Surat Thani foreign buyer transfers are reported up 220% year on year, with no year given. CHECK Thailand-wide, foreign condominium transfers fell 8.8% by unit count in H1 2026, to 6,533 units (nationthailand.com/REIC, 28 August 2026).

The verdict is rent, and keep renting

Do not buy on Koh Samui. That is the honest answer for almost everyone.

You cannot own the land under the villa you actually want. The lease that holds it runs 30 years and no further. Supply is rising while nightly rates fall, and resale of company-held villas has seized up. A permit here may be forged, on a slope nobody can agree is buildable.

Buy only if all four of these hold. You will be on this island more than ten years. You are inside the condominium quota, or on land a Thai lawyer has verified. The permit checks out against municipal records. And you could lose the money without it changing your life.

Proposals floated in June 2024 — 99-year leases, and a condominium quota raised from 49% to 75% — are still under review. Neither is law. An agent who sells you either as settled is misrepresenting the rule.

If one fails, rent here first and keep the capital liquid. A twelve-month lease costs 30 to 60% less than the holiday monthly rate, and ties you up for a year, not thirty. Read where people actually live on this island before signing.

Choosing between islands and mainland cities? Compare all ten cities in this series first.