As of 2026, our analysts estimate that off-plan pricing on Phuket carries a discount of roughly 15 to 25 percent relative to comparable ready-to-move-in units on the secondary market. That gap is a real risk premium - one the buyer absorbs from the developer at the moment of signing. We monitor construction progress across Bang Tao, Layan, Kamala, and Surin on Phuket, and across Bophut and Maenam on Koh Samui. Based on our data sets, approximately one in five active projects records a delay of more than six months against the original schedule.
Buyers entering the Thai off-plan market need to understand one structural reality from the outset: Thailand has no formal buyer-protection mechanism for construction-stage payments. Funds flow directly to the developer's account. The only real safeguards are contractual clauses and the developer's financial health. What follows is a stage-by-stage breakdown of how the transaction mechanics work and where the critical risk points sit.
Quick answer
- Off-plan discount vs. secondary market on Phuket: approximately 15-25% (as of 2026, per our market monitoring)
- Typical payment schedule: 5 to 7 tranches spread over 18 to 36 months of construction
- No buyer-protection mechanism for foreign buyers - payments go directly to the developer
- Most common delays occur during the fit-out and technical handover phase (3 to 9 months on average, based on our observations)
- Delay penalties in well-drafted contracts run 0.01-0.05% of contract value per day, but many contracts omit them entirely
- Right of rescission with full refund is a critical clause - without it, the buyer loses all negotiating leverage if the developer defaults
Options and scenarios
Payment schedule structures and how they distribute buyer risk
We regularly encounter three distinct payment schedule models across Phuket and Koh Samui. Each distributes buyer risk differently across the construction timeline.
Option A - Conservative schedule (buyer-favourable)
Under this model, the developer draws the majority of funds only after significant construction milestones have been reached. The reservation deposit is typically 50,000-100,000 THB. Contract signing carries a payment of 10-15% of the purchase price. Subsequent tranches of 10-15% each are tied to foundations, structural completion, and fit-out. The remaining 30-40% falls due at key handover. Total buyer exposure at the structural completion stage stays below 40% of the property value.
Option B - Standard market schedule
This is the most prevalent model in 2026. The reservation fee runs 100,000-200,000 THB, followed by 20-30% at contract signing, three milestone-linked instalments of 10-15% each during construction, and 20-25% at handover. Buyer exposure grows faster here - by structural completion, 50-60% of the total price has already been transferred.
Option C - Aggressive schedule (developer-favourable)
Some developers, particularly those in early presale phases, request 40-50% combined at reservation and contract signing, a further 30-40% during construction, and only 10-20% at handover. This is the highest-risk model for the buyer. If construction is abandoned at any point before the final tranche, the buyer may have already transferred 80-90% of the purchase price with no practical recourse mechanism.
The discount arithmetic: is the risk premium adequate
To ground this in a concrete example, consider a project in Bang Tao, Phuket, as of 2026. A 45 sq m apartment purchased off-plan at an early presale stage is priced at approximately 4.2 million THB. A comparable ready and furnished unit on the secondary market in the same subdistrict runs approximately 5.2 to 5.5 million THB. The discount is therefore roughly 19 to 24 percent, representing a nominal saving in the range of 1.0 to 1.3 million THB.
Whether that figure adequately compensates for 24 to 36 months of capital lock-up, potential delay risk, developer insolvency risk, and opportunity cost depends entirely on the developer's track record. Based on our analysis, the premium is justifiable - but only when the developer has a documented history of delivering completed projects on schedule.
On Koh Samui, specifically in Bophut and Maenam, off-plan discounts are somewhat narrower: approximately 12 to 18 percent. This reflects the smaller overall market scale and the higher proportion of villa-format projects, where margin structures differ materially from the condominium segment.
Comparison table
| Parameter | Option A - Conservative | Option B - Standard | Option C - Aggressive |
|---|---|---|---|
| Payment at contract signing | 10-15% | 20-30% | 40-50% |
| Cumulative exposure at structural completion | 30-40% | 50-60% | 70-80% |
| Payment at handover | 30-40% | 20-25% | 10-20% |
| Maximum potential loss if abandoned | Moderate | High | Very high |
| Buyer negotiating position | Strong | Moderate | Weak |
| Market frequency (2026) | Approx. 20% of listings | Approx. 55% of listings | Approx. 25% of listings |
| Typical developer profile | Large, established portfolio | Mid-size, 2-5 completed projects | Small or first-time market entrant |
Risks and mistakes
Stage 1 - Reservation and due diligence (month 0 to 1)
Risk: Reservation fees are almost always non-refundable. Buyers who pay before completing due diligence lose those funds if legal or title issues emerge afterwards. Our analysts verify the following as a minimum: Construction Permit status, Environmental Impact Assessment (EIA) report for projects exceeding 80 units, land title document (Chanote), and any registered mortgages or encumbrances on the land.
Common mistake: Buyers frequently commit reservation fees during a holiday visit, under time pressure from a sales presentation, without any prior verification of the project's legal standing.
Stage 2 - Contract signing (month 1 to 3)
Risk: Contracts drafted solely in Thai, or English versions that omit critical protective clauses, leave buyers exposed. Based on our contract reviews, the following provisions are non-negotiable:
- Delay penalties: minimum 0.01% of contract value per day for each day beyond the agreed completion date
- Right of rescission with full refund if delay exceeds 90 to 180 days
- Material and finish specification attached as a binding schedule to the contract
- Structural warranty of at least five years
- Payment schedule linked to construction milestones, not to calendar dates
Legal review of an off-plan contract by a qualified Thai law firm costs approximately 30,000 to 60,000 THB. Based on our observations, that cost is recovered many times over through identified clause deficiencies and negotiated amendments.
Stage 3 - Foundations and structural work (month 3 to 12)
Risk: Delays from monsoon conditions (Phuket's rainy season runs May to October), material supply disruptions, or labour shortages. In 2025, our analysts tracked an increase in structural steel costs in Thailand of approximately 8 to 12 percent year-on-year, which compresses developer margins and can affect project pacing.
Warning signal: If the developer requests accelerated payments or schedule modifications during active construction, treat this as a potential indicator of cash flow stress.
Stage 4 - Structural completion (month 12 to 18)
Risk: At this point, the buyer has typically transferred 50 to 70 percent of the purchase price. Abandonment at this stage produces the largest absolute loss. We verify whether the developer holds a Completion Guarantee from a licensed Thai bank or financial institution. In practice, fewer than 15 percent of developers in the Thai market offer this instrument.
Stage 5 - Fit-out and MEP installations (month 18 to 30)
Risk: This is the most frequent source of project delays. Fit-out progress depends on imported materials, subcontractor availability, and coordination quality. On Koh Samui, where there is no land bridge and all heavy materials arrive by ferry, logistical delays are structurally longer than on Phuket.
Stage 6 - Technical handover (month 30 to 36)
Risk: Discrepancies between actual finish quality and contractual specification, defects in MEP systems, and missing occupancy certificates (Certificate of Occupancy). We recommend engaging an independent building inspector for the handover process. Inspection fees typically run 15,000 to 30,000 THB and provide documented leverage for defect rectification.
Stage 7 - Title registration and ownership transfer
Risk: For foreign condominium buyers, the critical check is whether the Foreign Quota (capped at 49 percent of total floor area per building) remains available at the time of transfer. Transfer-related fees total approximately 6 to 7 percent of the assessed value, comprising Specific Business Tax (3.3%), Withholding Tax (1%), Transfer Fee (2%), and Stamp Duty (0.5%). Market practice in 2026 is to split these costs equally between buyer and developer, but this is negotiable and should be confirmed in the contract.
Recurring mistakes by international buyers
- Skipping developer background verification before paying the reservation fee
- Signing contracts without independent legal review and translation
- Accepting calendar-date payment schedules rather than milestone-linked ones
- Overlooking post-handover running costs: sinking fund (typically 500-800 THB per sq m, paid once), and monthly Common Area Maintenance fees (40-80 THB per sq m)
- Projecting rental yield in THB without factoring in exchange rate risk against the buyer's home currency
FAQ
Is off-plan buying in Thailand a reliable investment strategy?
It can be, but the risk profile is meaningfully different from buying a completed unit. Payments go directly to the developer without any buyer-protection mechanism. Based on our Phuket market data, developers with at least three previously completed projects show an on-time delivery rate of approximately 75 percent - which still implies a 25 percent probability of delay.
What off-plan discount can a buyer realistically expect on Phuket in 2026?
Our current estimates put the discount in the range of 15 to 25 percent relative to comparable secondary-market units. In premium subdistricts such as Layan and Surin, the discount tends to be narrower, around 12 to 18 percent. In growth areas including Rawai and Nai Harn, it can reach 20 to 25 percent.
Which contract clauses are most important for an off-plan buyer in Thailand?
The five provisions we treat as essential are: daily delay penalties (minimum 0.01% of contract value), right of rescission with full refund after 90 to 180 days of developer delay, a binding material and finish specification schedule, a minimum five-year structural warranty, and milestone-linked rather than date-linked payment tranches.
What happens to payments if the developer becomes insolvent?
The buyer becomes an unsecured creditor in insolvency proceedings. Recovery is typically slow and partial. This is precisely why assessing developer financial health before contract signing matters more than the size of the headline discount.
What does legal due diligence on an off-plan contract cost in Thailand?
A full contract review by a qualified Thai law firm runs approximately 30,000 to 60,000 THB. Based on our observations, the fee consistently identifies missing protective clauses and allows buyers to negotiate amendments before funds are committed.
Is the Koh Samui off-plan market worth considering?
The Koh Samui off-plan market is significantly smaller than Phuket's and is dominated by villa-format projects. Headline discounts are lower, at around 12 to 18 percent, while logistical risks during construction are higher due to the island's ferry-dependent supply chain. Among Samui subdistricts, Bophut and Maenam offer the most established rental demand profile.
What additional costs should a buyer budget for beyond the purchase price?
Beyond the headline price, buyers should budget for: transfer fees (approximately 3 to 3.5 percent when costs are split with the developer), sinking fund (500-800 THB per sq m, one-time), monthly CAM fees (40-80 THB per sq m), furniture and fit-out if not included (approximately 200,000 to 500,000 THB for a 45 sq m apartment), and legal review costs.
How do our analysts verify developer credibility?
Our standard due diligence covers: corporate registration status with the Department of Business Development (DBD), the full list of previously completed projects, verified owner feedback from those earlier developments, land title status at the Land Office, and any recorded litigation or disputes involving the developer entity.
How is rental income from Thai property taxed for foreign residents?
Tax treatment depends on the buyer's country of residence and the applicable double taxation agreement. Thailand and a number of countries have bilateral agreements in place that govern which jurisdiction has primary taxing rights over rental income. We recommend obtaining advice from a qualified tax professional familiar with both Thai tax law and the buyer's home-country obligations before committing to a purchase.
Researching property in Phuket or Koh Samui? Get in touch - our analysts will prepare a data brief for your shortlisted location.