Thai Company Monthly Compliance Calendar: Every Deadline

Running a company in Thailand comes with a steady rhythm of filing obligations, and if you are new to it, the sheer number of deadlines can feel overwhelming. The Thai Revenue Department, Social Security Office, and Department of Business Development each have their own schedules, and missing even one submission can trigger fines, surcharges, or complications down the line. This guide lays out the core monthly compliance requirements in plain language, so you know what is due, when it is due, and roughly what is involved.

Understanding Who the Filings Are For

Not every obligation applies to every company. The filings you are responsible for each month depend on whether you have employees, whether your business is VAT-registered, and what type of income your company earns or pays out. A small trading company with three staff and VAT registration will have a different monthly checklist than a holding company with no employees. That said, most active Thai limited companies will encounter at least three of the obligations covered below, and many will deal with all of them regularly.

VAT Return (PP.30): Due by the 15th of Each Month

If your company is registered for VAT, which is required once annual revenue reaches 1.8 million baht, you must file a monthly VAT return using the form known as PP.30. This return reports the output VAT you collected from customers during the previous month and the input VAT you paid to suppliers. The difference either results in a VAT payment to the Revenue Department or, if input VAT exceeds output VAT, a credit you can carry forward or request as a refund.

The deadline for paper filing is the 15th of the following month. If you file online through the Revenue Department's e-filing system, you typically get an extended deadline, currently the 23rd of the following month, though you should confirm this each year as the Revenue Department can adjust it. Late filing incurs a surcharge of 1.5 percent per month on any tax owed, plus a separate fine of up to 2,000 baht for the late submission itself.

Withholding Tax Returns (PND.1 and PND.3): Also Due by the 7th or 15th

Withholding tax is one of the areas that catches new business owners most off guard. When your company pays salaries to employees, or pays fees, rent, or certain services to individuals or other businesses, you are legally required to deduct a portion of that payment and remit it to the Revenue Department on the recipient's behalf.

For salaries paid to employees, you file form PND.1. For payments made to non-employees such as freelancers, contractors, or service providers who are individuals, you use form PND.3. If payments are made to juristic persons such as other companies, the form is PND.53. Paper filing deadlines fall on the 7th of the following month, while e-filing extends this to the 15th. The withholding tax rates vary depending on the type of payment, so it is worth getting clear on which rate applies to each category of expense your company regularly incurs.

Social Security Contributions: Due by the 15th of Each Month

Any company that employs Thai nationals must register with the Social Security Office and make monthly contributions. Both the employer and the employee contribute a percentage of the employee's monthly salary, subject to a ceiling on the salary base. The employer deducts the employee's portion from their pay and then submits the combined contribution to the Social Security Office along with the required form.

The deadline is the 15th of the following month. Missing this deadline results in a surcharge calculated as a percentage of the outstanding amount per month, which can add up quickly if payments are repeatedly late. It is also worth noting that contribution rates and the salary ceiling have changed over the years, so it is good practice to confirm the current figures at the start of each year rather than assuming they remain the same.

Monthly Accounting Records: No Filing, But Still Non-Negotiable

This one does not involve submitting anything to a government office each month, but it belongs on your compliance calendar nonetheless. Thai law requires companies to maintain proper accounting records in Thai language, prepared in accordance with Thai accounting standards. Your accounts need to be kept up to date on a monthly basis so that annual financial statements can be prepared accurately and audited by a certified auditor.

If you let bookkeeping slip for several months and then try to reconstruct it at year-end, you create errors, delays, and unnecessary stress ahead of your annual filing deadlines. More practically, staying on top of monthly accounts also gives you a clear picture of your company's financial position throughout the year, which matters if you are managing cash flow or making decisions about hiring or investment.

Annual Obligations That Start With Monthly Habits

Two major annual deadlines sit downstream from your monthly compliance work. The first is your corporate income tax return, which covers the full financial year and is due within 150 days of your accounting period end. The second is your audited financial statements, which must be submitted to the Department of Business Development. Both of these are far easier to complete accurately and on time when your monthly bookkeeping, VAT returns, and withholding tax filings have been done properly throughout the year.

Think of monthly compliance as the foundation. If each month's records are clean and submitted on time, your accountant or auditor has what they need to close out the year efficiently. If filings have been missed or records are incomplete, it typically means additional time, additional cost, and sometimes explanations to the Revenue Department.

A Simple Way to Stay on Top of It All

The most reliable approach for small business owners and foreign company directors is to work with a local accounting firm that manages the monthly submission schedule on your behalf. This removes the burden of tracking multiple deadlines across different government departments, ensures that forms are completed correctly in Thai, and means that any changes to rates or procedures are handled without you needing to monitor them yourself.

If you do want to stay closely involved, a basic compliance calendar with three key dates each month, the 7th, the 15th, and the 23rd, covers most of the regular obligations. Marking these in advance and checking what needs to be prepared the week before each date is a straightforward habit that prevents most of the common compliance problems small companies face.