When is a buyer or seller 'in default'? Due dates and demand notices under CCC 203-205

When does a late buyer or seller legally count as 'in default'? Under CCC Section 204, if the debt is due and the creditor gives a warning, the debtor is in default if still not performing. If the contract fixes a time by calendar, the debtor is in default on that date without any warning. Default is the trigger for many remedies, so the date wording in your contract matters.

What Sections 203-205 say

• Section 203 — no time fixed — where no time for performance is fixed or inferable, the creditor may demand performance at once and the debtor may perform at once. Where a time is fixed, the creditor generally cannot demand earlier, though the debtor may perform earlier.
• Section 204 — default — after maturity, the debtor is in default through the creditor's warning. If a time by calendar is fixed, the debtor is in default without warning.
• Section 205 — no fault — a debtor is not in default so long as non-performance results from a circumstance for which they are not responsible.

Why it matters for property deals

• Instalments to a developer or seller — a payment schedule with calendar dates puts a late buyer in default without a reminder; vague wording ('upon completion of the foundation') may need a written warning first.
• Transfer day — if the SPA says 'transfer on or before 30 November', a seller who does not appear is in default from the next day. If it says 'within a reasonable time', a written demand is the safer route. See the Land Office registration day.
• Remedies that follow — default interest (statutory rate), penalty clauses and rescission generally depend on a party being in default; the precise conditions for each are in those guides.
• Contractor delays — the same logic applies to a builder's completion date; see terminating a construction contract.

Practical steps

• Put exact calendar dates on every payment and transfer deadline.
• If a date is open-ended, send a dated written demand giving a reasonable deadline, ideally in Thai and English, and keep proof of delivery.
• Record any reason you could not perform (Section 205), such as a Land Office closure or the other side's missing documents, in writing at the time.
• Do not stop paying or declare termination until a Thai lawyer has checked whether the other side is actually in default.

Takeaway: default is a legal status, not just lateness. Calendar dates make it automatic; otherwise a clear warning does. The section texts are unofficial English translations and the Thai text governs, so confirm the details with a Thai lawyer.