The 49% rule is the single most-cited Thai property law number among foreign buyers, and the most frequently misunderstood. The rule itself is short — Section 19 of the Condominium Act 1979 — but the calculation method, what it includes, what it excludes, and what to do when a building hits the cap are details that drive real transaction outcomes.
What Section 19 actually says
The Condominium Act B.E. 2522 (1979), Section 19, caps the aggregate floor area of saleable condominium units that may be foreign-owned at 49% of the total saleable floor area of the registered condominium project. The remaining 51% must be owned by Thai nationals or qualifying Thai juristic persons.
The cap is statutory. It is not negotiable, not waivable by the developer, not avoidable by the juristic person, and not modifiable by the Land Office. A registration that would push the building above 49% foreign-owned is refused.
How the 49% is calculated
Three calculation rules drive the practical outcomes:
1. By floor area, not unit count. A 200-unit building with one 1,000 m² penthouse and 199 units of 50 m² each has 11,000 m² of saleable area total. If foreigners own the penthouse plus 80 of the smaller units, that’s 1,000 + 4,000 = 5,000 m² — about 45%, under the cap. If foreigners owned the penthouse plus 100 small units, that’s 6,000 m² (~55%) — over the cap, and the last registrations would have been refused. The mix of which units foreigners buy matters as much as how many.
2. Saleable units only. Common areas, parking, lobbies, hallways, gym, pool, lifts, mechanical rooms, and amenities are excluded from the denominator. Only the saleable unit floor area counts. A building with extensive amenity space has a smaller effective denominator, so the 49% is reached at a lower absolute foreign-owned area than a building with minimal common space.
3. Per registered condominium project. The cap is measured per condominium title (the registered project), not per developer and not per building. Two adjacent buildings in the same compound that are registered as separate condominium projects have separate 49% quotas. A single project that includes multiple buildings has a single quota. The juristic person can confirm the registration scope.
What “Thai-owned” actually means for quota purposes
The 51% Thai side counts ownership by:
- Thai natural persons (Thai citizens)
- Thai juristic persons that are Thai-majority owned per the Condominium Act tests
- Foreigners who qualify under specific exemptions (see below)
A unit owned by a Thai-majority company counts toward the 51% Thai side, regardless of who owns the company’s foreign minority shares. This used to enable workaround structures where a foreigner held units indirectly via a Thai company. The structure is technically legal under the Condominium Act but exposes the same nominee-shareholder risk that affects Thai-majority companies holding land — and the 2024–2025 enforcement wave applies here too.
How to check the current foreign-owned percentage
The juristic person of any registered condominium maintains a register of unit ownership including each unit’s owner nationality. The foreign-quota status as of any given date is calculable from this register.
Three practical points:
Always require it in writing. A verbal “we have plenty of foreign quota” from a sales agent is not a confirmation. Require the juristic person to issue a current foreign-quota certificate (or Letter from Juristic Person) stating the percentage of saleable floor area currently registered to foreigners, dated within the last 30 days. The Land Office requires this letter on transfer day anyway.
Verify before paying meaningful deposits. A reservation fee of THB 100k–500k is reasonable to lose if you change your mind. It is not reasonable to lose because the building hit 49% between your reservation and your transfer. Get the foreign-quota certificate before paying any deposit beyond the initial reservation.
Track the trend, not just the snapshot. A building at 35% foreign-owned with a phase 2 launch coming may consume the remaining quota quickly. A building at 47% with no new launches may have stable quota for years. The juristic person’s certificate gives you the snapshot; the developer’s marketing pipeline tells you the trajectory.
What happens when a building reaches 49%
When a registered project is at the 49% cap, the Land Office refuses any further foreign freehold registrations. New foreign buyers have three options:
1. Wait for quota to open. When a foreign-owned unit is sold to a Thai national or its title is restructured to leasehold, quota opens up. Some developers maintain waiting lists; some buildings have natural turnover that creates regular openings. This is often slow.
2. Buy on leasehold. A registered lease does not count toward the 49% — the freehold owner remains Thai for quota purposes. Foreigners who want a specific unit in a quota-saturated building can take a 30-year registered lease instead. The trade-offs (resale market is smaller, finite term, no perpetual ownership) are covered in Freehold vs leasehold property in Thailand — what's the difference and which to choose.
3. Pick a different building. Most projects have foreign-quota space. The shortage is concentrated in a handful of high-demand buildings — branded residences, beachfront, foreign-buyer-marketed projects in Bang Tao and Laguna. Less-marketed projects often have substantial unused quota.
When the developer says “we’ll sort the quota”
A developer who can’t produce a foreign-quota certificate in writing but assures you “we’ll work it out” is offering nothing. Common variants:
- “We’ll register the unit to one of our Thai staff first and transfer to you later.” This is a nominee structure, exposes the foreigner to nominee-prosecution risk under the Land Code, and the buyer has no recourse if the Thai staff member refuses to transfer or makes claims later.
- “The building isn’t fully registered yet so the cap doesn’t apply.” Misleading. The cap applies once the building is registered as a condominium and the units are sold. A pre-registration sale does not bypass it; it just defers the calculation.
- “We have a Thai partner buying back from foreigners as needed.” This is workable in a regulated way through a structured fund but is rarely what’s actually being offered. Verify with documentation.
In all three cases, walk away. The developer either doesn’t understand the rule (bad sign) or is trying to push the registration risk onto you (worse sign).
The 75% proposal status
Since late 2024, the Pheu Thai government has floated raising the 49% cap to 75%, sometimes in geographically-targeted variants (Phuket only, Bangkok unchanged) or price-floor variants (units above THB 10M only). A parallel proposal would extend the maximum lease term from 30 to 99 years.
As of 2026, neither has been enacted. Both face strong political opposition on sovereignty and Thai-affordability grounds, including from the Senate. The proposals have moved through cabinet study but not through the legislative pipeline. Industry lobby (Thai Real Estate Association, REIC) continues to push.
For planning, treat 49% as the binding rule until publication in the Royal Gazette. A draft proposal is not a law, and Thai property law has shown stability in its core rules even when amendments are floated. If the 75% does happen, existing freehold owners gain — secondary-market liquidity improves and prices likely rise. But don’t underwrite an investment on the assumption.
What this means for buyers in 2026
Three rules cover most cases:
- Always require a written foreign-quota certificate before paying any deposit beyond the initial reservation. Date within 30 days, issued by the juristic person.
- Don’t buy a quota-blocked building on a verbal “we’ll sort it” assurance. If freehold isn’t immediately available, your options are leasehold (with all its trade-offs) or a different building.
- Don’t underwrite the 75% proposal as imminent. Plan as if 49% holds; treat any change as upside.
Full ownership rules: Foreign property ownership in Thailand — what you can and cannot own. Lease alternative: Freehold vs leasehold property in Thailand — what's the difference and which to choose. Transaction sequence: How to buy property in Thailand — step-by-step guide for foreigners.