Unpaid Land and Building Tax in Thailand: the registration bar and seizure power behind a missed bill

What actually happens if Land and Building Tax on a Koh Phangan property goes unpaid? Two separate consequences follow, one immediate and one that escalates on a fixed timeline — both set out in Chapter 8 of the Land and Building Tax Act B.E. 2562 (2019), "Tax in Arrears" (Sections 58–67).

First, and immediately: Section 59 blocks your next transfer

The moment a payment is missed past its deadline, it becomes "tax in arrears" under Section 58. Section 59 then bars the Land Office from registering any transfer of rights — a sale, a gift, adding a co-owner — over that land or building while the arrears sit unpaid. Section 60 requires the local authority to report arrears data to the Land Office by June each year, feeding exactly this check. In practice, this means unpaid LBT isn't just a debt the owner carries privately; it's a live block on the next registration at the Land Office, which is why it belongs in due diligence on both sides of a deal — a seller who owes tax can't close, and a buyer who doesn't check risks inheriting a stalled transaction.

Then: the warning notice and the 90-day countdown to seizure

• Section 61 — the local authority issues a written warning notice to taxpayers in arrears, due by May each year.
• Section 62 — if the arrears remain unpaid 90 days after that notice, the local administrator gains the power to issue a written order to seize, attach and auction the taxpayer's property to recover the tax, surcharge and costs. Where the local administrator is a municipal or subdistrict-level official — the level at which Koh Phangan's own local government sits — provincial governor approval is required before this power can be used.
• Section 63 — the local authority also has powers of inspection and investigation to locate and verify property for this purpose.
• Section 64 — a seizure is lifted once the tax, surcharge and costs are paid in full.
• Section 65 — the local administrator can't proceed to auction while an appeal against the assessment, or a related court case, is still pending.
• Section 66 — auction proceeds first cover the tax, surcharge, penalty and the costs of the seizure/auction itself; any remainder goes back to the owner.

That Section 65 pause is narrower than it sounds: it only stops the auction once a seizure order already exists — it doesn't touch the payment deadline itself. Disputing a Land and Building Tax assessment still doesn't pause the underlying obligation to pay by the statutory deadline; it only pauses a seizure that's already been ordered from proceeding to sale.

The late-payment surcharge is separate from — and smaller than — the misdeclaration penalty

Section 70 sets a flat late-payment surcharge of 1% per month on the arrears (any part of a month counts as a full month), reduced to 0.5% per month if the local authority approves a payment-extension arrangement — and capped so the surcharge itself can never exceed the tax amount owed. This is a distinct, smaller mechanism from the separate penalties under Sections 68–69 (commonly cited in the 10–40% range), which apply to different failures — such as under-declaring or misrepresenting a property in the assessment process — not simply paying late. The two get conflated in some secondary sources; they're not the same provision.

Why this matters more for a buyer than it looks

This is an entirely different mechanism from buying a property at a Legal Execution Department auction, which is a judicial process under the Civil Procedure Code, triggered only after a court judgment — a mortgage default, for instance. The LBT arrears process is non-judicial: the local administrator runs it directly under the LBT Act itself, with no court order required at any stage. Because liability follows the property and the registration bar applies regardless of who currently holds title, confirming a clean, paid-up LBT receipt is worth doing alongside a title search — before a transfer day gets scheduled, not after it stalls.