Report Tax Evasion in Thailand Anonymously: The Channels

TL;DR

Suspected tax evasion is reported to the Revenue Department (กรมสรรพากร). Channels include the 1689 hotline, the e-form on rd.go.th, and the Inspector-General's Office. Revenue Code B.E. 2481 (1938) §123/4 provides an informant reward of up to 15% of the tax actually recovered, capped per the Notification. Reports can be anonymous, but rewards require identification. Confidentiality of informants is statutorily protected.

Reporting Channels

• Hotline 1689 (Revenue Department).
• E-form via rd.go.th → "แจ้งเบาะแสภาษี" (tax tip-off).
• Written letter to the Inspector-General, Revenue Department.
• In-person at any Area Revenue Office.
• Anti-Corruption sister channels for officer-corruption-flavoured cases (NACC).

What to Include

• Identification of the taxpayer (name, address, tax-ID where known).
• Description of the suspected evasion (under-reporting, non-declaration, fictitious invoices).
• Supporting documents or references (invoices, bank statements).
• Time period at issue.

The Reward System

Protections + Risks

• Statutory confidentiality (Revenue Code §10).
• Civil-defamation risk if the report is malicious and false — Criminal Code B.E. 2499 (1956) §326-328.
• If reporter is the taxpayer's employee, employment-law retaliation protections under the Labour Protection Act B.E. 2541 (1998) may also apply.

Common Mistakes

• Reporting without any documentary basis — likely to be discounted.
• Identifying the reporter to the taxpayer informally — destroys protection.
• Expecting fast resolution — audits commonly take 12+ months.

FAQs

1. Is the reward reliable?

Reward is paid by the Revenue Department per published rules; the cap and discretion under §123/4 apply.

2. Can foreigners report?

Yes — no nationality restriction on reporters.

How a Tip-Off Becomes an Audit

Reporting suspected evasion is only the first link in a long chain. The Revenue Department triages the tip, and if there is a substantive documentary basis it may open an audit of the taxpayer; assessment, any penalties, and actual recovery of the tax follow only if the audit stands up. Because the informant reward is tied to tax actually recovered, a vague or unsupported allegation rarely goes anywhere — the useful reports identify the taxpayer clearly and attach or point to concrete evidence (fictitious invoices, undeclared receipts, bank movements) covering a defined period.

Anonymity, Rewards and the Downside Risk

There is a genuine tension between anonymity and reward: you can report without giving your name, but claiming any informant reward requires you to identify yourself, and informant confidentiality is protected by statute rather than by staying anonymous. Two cautions matter. First, a knowingly false or malicious report can expose the reporter to defamation liability. Second, an employee who reports their employer may have separate labour-law protection against retaliation, but should take advice before acting. Audits routinely take a year or more, so a reward — where it comes at all — is a slow outcome, not a quick payout.

Related Reading

• Whistleblower Protections
• Tax Law Hub