A complete and updated guide to monthly tax filing for business owners in 2025 — including key tax types, deadlines, and best practices.
Monthly tax filing is a crucial obligation for all business owners — whether you're a limited company or a registered partnership. In this article, we’ll answer common questions such as:
• What taxes do we need to pay each month?
• How much tax do we owe?
• When are the filing deadlines?
The Importance of Accurate and Timely Tax Filing
Filing taxes correctly and on time is something no business owner should overlook. Here’s why it matters:
- Builds business credibility: Transparent operations help strengthen your reputation with clients and partners
- Avoids penalties: Filing late or with errors can result in fines and added interest
Beyond these reasons, tax filing is a mandatory duty for every business — big or small. If you're unsure how to structure your company's tax process or want to improve your current approach, this guide is for you. And if you’ve already decided to seek help, METI offers full-service consulting and accounting support, backed by licensed CPAs with over 30 years of experience.
Monthly Tax Obligations
Business owners must submit different tax forms to the Revenue Department each month, depending on the type of tax. Here are the main ones:
1. Withholding Tax (WHT)
Withholding Tax refers to income tax that must be deducted at source by the payer and submitted to the Revenue Department based on applicable rates.
Examples of Expenses Subject to Withholding Tax
- Service fees
- Contract labor
- Transport charges
- Advertising costs
- Rent
Required Documents
1.Tax forms for withholding must be filed according to income type:
- PND.1
For employee salaries and wages — income under Section 40(1) and (2) - PND.2
For payments classified under Section 40(3) and (4) - PND.3
For payments to individuals such as freelancers, landlords, or other non-salaried earners - PND.53
For payments to legal entities — such as fees paid to companies for services
- Withholding Tax Certificate (Form PND.50)
Issued to payees when tax is withheld. Must include payer/payee details and withholding amount.
- If the employee works through year-end: Issue by February 15 of the following year
- If the employee resigns mid-year:Issue within 1 month of termination
- For other income (Section 40(3)–(8)):
Issue immediately each time tax is withheld
Filing Deadlines
- Paper submission: by the 7th of the following month
- Online submission: by the 15th of the following month
Example Scenario
On August 10, Company Alpha pays a freelancer 20,000 THB for web design.
- WHT rate: 3% → 600 THB withheld
- Freelancer receives: 19,400 THB
- Company Alpha submits PND.3 and the 600 THB by September 15 (online)
A Withholding Tax Certificate (Form PND.50 ) dated August 10 is issued to the freelancer
2. Value Added Tax (VAT)
VAT (7%) is imposed on the sale of goods and services. Businesses registered for VAT are required to file monthly.
Conditions
- Non-VAT registered businesses are exempt from filing
- VAT-registered businesses must file monthly, regardless of activity
Required Documents
- Value Added Tax (VAT) Form
- PP.30
- Monthly VAT filing form — summarizing input and output tax. Required if annual revenue exceeds 1.8 million THB. Must be filed by the 15th of the following month.
- PP.36
- For cases where the buyer files VAT on behalf of foreign or temporary vendors not doing regular business in Thailand.
- PP.30
2. Sales Tax Report and Tax Invoices (Output VAT)
- VAT can be claimed within 6 months of the invoice date. Claims made outside the month of issue must have valid reasons (e.g. trade customs, late receipt).
3. Output Tax Report & Sales Invoices
- Must reflect monthly sales and match the issued invoice dates.
4.Inventory & Raw Material Report
- Tracks stock quantities and movements for proper inventory control.
Filing Deadlines
- Paper submission: by the 15th of the following month
- Online submission: by the 23rd of the following month
Example Scenario
In August 2023, Company Beta generates 200,000 THB in sales.
- Output VAT: 14,000 THB (7%)
- Input VAT: 7,000 THB (on 100,000 THB worth of purchases)
Tax Payable = 14,000 – 7,000 = 7,000 THB
File PP.30 in September to report and pay this amount
- Monthly tax filing for limited companies and partnerships isn't complicated — as long as you stay organized and compliant.
Doing so keeps your business stable and builds long-term credibility.
Examples of Key Tax Form
1. PND.1
2. P.N.D.2
3. PND.3
4. PND.53
5. PP.30
6. PP.36
How to Prepare for Monthly Tax Filing
- Organize all required documents:
Clearly separate purchase invoices, sales invoices, receipts, and related expenses. - Double-check data accuracy:
Verify all forms and calculations to reduce filing errors. - Use accounting software or expert support:
Streamlines the process and ensures accurate reporting.
Common Tax Filing Pitfalls to Avoid
- File on time to avoid penalties
- Keep submission proof for future audits
- Stay informed on rules for partnerships and updated requirements
Filing monthly taxes properly helps avoid fines and spreads your annual tax burden more evenly. If you're unsure about any part of the process, consulting a tax expert is the smart move.
Related Search Terms
- Corporate Tax
- Withholding tax filing
- How much tax does a company pay?
- What is withheld tax?
- Partnership tax filing
