Salary plus side income: how should you prepare your tax return?

1. Classify each income source

Employment income falls under section 40(1). Side work may involve services, royalties, rent, liberal professions or trading. Do not put every freelance payment under section 40(8) simply because it is outside employment. Section 40

Preparation tip: record the activity, payer, contractual responsibilities and receipt date. Bring unclear classifications to your accountant before choosing expense treatment.

2. Identify the annual return

PND91 covers section 40(1) employment income only. Salary plus other income that must be combined generally requires PND90, subject to filing thresholds and exceptions. Return types

No tax payable does not necessarily remove the filing obligation. Filing thresholds and tax after deductions are separate questions. Filing thresholds

3. Collect gross income and withholding records

• Relevant section 50 bis withholding certificates.
• Contracts, invoices, receipt evidence and platform statements.
• Expense records separated by activity.
• Allowance evidence and tax already filed or paid.

A net transfer may be below gross income because tax was withheld. Match it to the certificate. Eligible withholding is credited against calculated tax rather than deducted again as an expense. Sections 50 bis and 60

4. Separate expenses from allowances

Expenses depend on income classification; personal allowances depend on individual eligibility and tax-year rules.

Sections 40(1) and 40(2) share a 50% standard expense deduction capped at THB 100,000 in total. They do not each receive a separate cap. Check other categories individually. Expense rules

Related: Tax bands and annual allowances

5. Check half-year filing

Qualifying income under sections 40(5)–(8) received in January–June can create a PND94 obligation, normally due in September. Verify the actual year and filing-channel announcements. Section 56 bis · PND94 forms

Reconcile income, expense treatment and tax credits before filing. Foreign income and items eligible for separate treatment need further review; this article covers basic preparation.