Within two months after the end of the first six months. For a calendar year: 31 August. Filing online gives 8 more days.

P.N.D.51 Half-Year Corporate Income Tax Return

The half-year corporate income tax return, filed and paid within two months after the first six months of the accounting period. It is an advance on the year's tax. The amount paid is credited against the P.N.D.50 for the same year, so a good estimate avoids a large balance later.

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AccountsOS tracks your tax and filing deadlines, keeps the books and handles invoicing for Thailand businesses, in plain English. Ask Finn about yours, no signup needed.

Who this applies to

  • Companies and juristic partnerships with a full 12-month accounting period

What to file

Form P.N.D.51, usually on half of the profit estimated for the full year. Some companies, such as listed companies, use the actual six-month result.

How to file

On paper or online through e-Filing. AccountsOS does not submit it. Finn keeps the date on your calendar, reminds you before it falls due and shows the figures from the books your accountant needs.

Payment due

With the return.

Penalties for missing this deadline

The Revenue Department allows a 25% margin of error on the estimate and charges a surcharge when it falls short by more. Late tax carries 1.5% per month.

Filing checklist

  • Review the first six months in the ledger
  • Agree the full-year estimate with your accountant
  • File and pay by 31 August (calendar year)
  • Check whether the SME rates apply to the estimate
  • Keep the receipt for the P.N.D.50 credit

Documents you'll need

  • The ledger for the first six months
  • Last year's P.N.D.50, as a starting point for the estimate
  • The full-year budget or forecast

Common mistakes to avoid

  • Underestimating the full-year profit by more than 25%
  • Forgetting to credit P.N.D.51 against P.N.D.50
  • Missing the date because the accounting period does not start in January
  • Not keeping the working behind the estimate

Never miss a Thailand deadline

AccountsOS tracks every Revenue Department (กรมสรรพากร) and Department of Business Development (กรมพัฒนาธุรกิจการค้า, DBD) deadline and reminds you weeks ahead.

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