Thailand Personal Income Tax Deduction Guide

Thailand's Personal Income Tax is not calculated directly based on your total annual salary. Instead, allowable employment expenses and eligible tax deductions must first be deducted before applying the progressive tax rates.

The calculation can be simplified as follows:

Annual Income − Allowable Expense Deduction − Eligible Tax Deductions = Taxable Income

(The applicable Personal Income Tax rate is then applied to the taxable income to determine the final tax payable.)

Example

Assume an employee receives a total annual income of THB 420,000, including salary, bonuses, allowances, and other employment income.

Step 1: Employment Expense Deduction

Employment income is entitled to a standard expense deduction of 50% of income, subject to a maximum deduction of THB 100,000.

For an annual income of THB 420,000:

THB 420,000 × 50% = THB 210,000

However, since the maximum allowable deduction is THB 100,000, the employee may deduct only:

THB 100,000

Remaining income after the expense deduction:

THB 420,000 − THB 100,000 = THB 320,000

Step 2: Personal and Other Tax Deductions

After deducting employment expenses, taxpayers may further claim eligible personal and family-related tax deductions.

Examples include:

• Personal allowance: THB 60,000 per taxpayer per year

• Social Security contributions: based on the actual amount paid

• Eligible life insurance or health insurance premiums

• Spouse, children, and parental support allowances (subject to qualifying conditions)

• Home mortgage interest (up to THB 100,000 per year, subject to eligibility)

Assume the employee is eligible for the following deductions:

• Personal allowance: THB 60,000

• Social Security contributions: THB 9,000

Remaining taxable income:

THB 320,000 − THB 60,000 − THB 9,000 = THB 251,000

Using a taxable income of THB 251,000 as an example:

• The first THB 150,000 is tax-exempt.

• The remaining amount:
  THB 251,000 − THB 150,000 = THB 101,000

• This portion is taxed at 5%.

Therefore, the annual Personal Income Tax payable would be approximately:

THB 101,000 × 5% = THB 5,050

In practice, employers generally withhold Personal Income Tax each month based on the employee's estimated annual income.

When the annual tax return is filed, the final tax liability is recalculated using the taxpayer's actual annual income together with all eligible deductions.

• If the total tax already withheld exceeds the final tax payable, the taxpayer may apply for a tax refund.

• If the tax withheld is less than the final tax payable, the taxpayer will be required to pay the outstanding balance.

1. Personal Allowance

Every taxpayer who legally files personal income tax in Thailand is entitled to a:

THB 60,000 personal allowance.

This is a standard personal allowance and generally does not require proof of actual expenses.

2. Spouse Allowance

If the taxpayer's spouse has no taxable income during the tax year and the couple is legally married, the taxpayer may claim:

THB 60,000

If the couple is only living together without legal marriage registration, the spouse allowance generally cannot be claimed.

3. Child Allowance

Each eligible biological child generally qualifies for a deduction of:

THB 30,000

For the second and subsequent biological children born in or after 2018, an additional:

THB 30,000

may be claimed, subject to the applicable conditions.

Therefore, the maximum deduction for each eligible child is:

THB 60,000

Adopted children are subject to additional eligibility requirements and limitations based on the number of adopted and biological children.

4. Parent Allowance

Taxpayers supporting their own parents, or the parents of a spouse with no taxable income, may claim:

THB 30,000 per parent

The following conditions generally apply:

• The parent must be 60 years of age or older.

• The parent's annual income must not exceed THB 30,000.

• The same parent cannot be claimed by multiple children.

• Supporting documents and proof of relationship are required.

5. Allowance for Supporting Disabled or Incapacitated Persons

Taxpayers who care for an eligible disabled or legally incapacitated person may claim:

THB 60,000 per person

The taxpayer is generally required to be the legally registered caregiver and provide disability certificates, medical documents, and any other documents required by the Revenue Department.

6. Pregnancy Check-up and Childbirth Expenses

Medical expenses for prenatal care and childbirth incurred by the taxpayer or a spouse with no taxable income may be deducted based on the actual amount paid.

Maximum deduction per pregnancy: THB 60,000

Hospital receipts and supporting documents should be retained for tax filing purposes.

1. Life Insurance Premiums

Premiums paid for qualifying life insurance policies are deductible based on the actual amount paid, up to a maximum of:

THB 100,000

Please note that not all insurance policies qualify. The policy term, insurance type, and insurance company must meet the requirements set by the Thai Revenue Department.

2. Health Insurance Premiums

Health insurance premiums paid for the taxpayer are deductible based on the actual amount paid, up to:

THB 25,000

However, the combined deduction for life insurance and health insurance premiums is generally capped at:

THB 100,000

Example:

• Life insurance premium: THB 90,000

• Health insurance premium: THB 25,000

• Total premiums paid: THB 115,000

Since the combined deduction limit is THB 100,000, only THB 100,000 may be claimed.

3. Health Insurance for Parents

Health insurance premiums paid for the taxpayer's parents or the parents of a spouse with no taxable income are deductible based on the actual amount paid.

Maximum combined deduction: THB 15,000

The parents must generally satisfy the applicable age, income, and insurance eligibility requirements.