Thai Company Monthly Compliance Calendar for Beginners
<p>Running a company in Thailand comes with a steady rhythm of tax filings, social security contributions and statutory reports that repeat month after month, quarter after quarter. If you are new to owning or managing a Thai-registered business, the sheer number of deadlines can feel overwhelming at first. The good news is that once you understand the pattern, compliance becomes predictable. This guide walks you through every recurring obligation in plain language, so you know what is due, when it is due and why it exists.</p> <h2>Why Filing Deadlines Matter More Than You Might Think</h2> <p>In Thailand, missing a filing deadline is not simply an administrative inconvenience. The Revenue Department, the Social Security Office and the Department of Business Development each impose their own late penalties and surcharges. For tax filings specifically, a surcharge of 1.5 percent per month is added to any unpaid tax, and a separate penalty on top of that can apply depending on the circumstances. Even a nil return, meaning a filing where no tax is actually owed, must be submitted on time or a fine can still be issued. Understanding the calendar is therefore not just good practice; it is how you protect your company from unnecessary costs.</p> <h2>The Core Monthly Filings You Will See Every Single Month</h2> <p>Two obligations repeat every calendar month without exception for most Thai companies. The first is withholding tax, filed on the Revenue Department form known as PND 1 for payments made to employees and PND 3 for payments made to individual contractors or service providers. If your company pays salaries or engages freelancers, you are required to withhold a portion of that payment, remit it to the Revenue Department and file the accompanying return. The deadline for these forms is the 7th of the following month if filing in person at a Revenue Department office, or the 15th if filing online through the Revenue Department's e-filing system.</p> <p>The second monthly obligation is Value Added Tax, or VAT, if your company is VAT-registered. Businesses with annual revenue above 1.8 million baht are required to register for VAT, and once registered they must file form PP.30 every month declaring output tax collected from customers and input tax paid to suppliers. Again, the deadline is the 7th of the following month for paper filing or the 15th for online filing. If your company is not yet VAT-registered because revenue is below the threshold, this filing does not apply to you, but it is worth knowing the threshold so you can register in time when your turnover grows.</p> <h2>Social Security: A Monthly Obligation Tied to Your Payroll</h2> <p>If your company has employees, including yourself as a working director in many cases, you are required to contribute to the Social Security Fund each month. Both the employer and the employee contribute a percentage of the employee's monthly salary, subject to a salary cap that the Social Security Office sets and reviews periodically. The combined contribution is remitted to the Social Security Office and the deadline falls on the last day of the month following the payroll month. Social security filings are separate from Revenue Department filings and go through the Social Security Office's own online portal. Falling behind on social security contributions can affect your employees' right to claim benefits, so this one has a human impact beyond the financial penalties.</p> <h2>Quarterly and Semi-Annual Filings to Plan Ahead For</h2> <p>Not every obligation arrives monthly. Corporate income tax has two key annual moments, but one of them requires a mid-year estimate. Companies in Thailand must file a half-year corporate income tax return using form PND 51 within two months of the end of the first six months of their accounting year. For companies using a January to December accounting year, this means PND 51 is due by the end of August. The amount you pay at this stage is essentially an advance payment based on an estimate of your full-year profit. Getting this estimate reasonably accurate matters because underpaying by more than a certain margin can trigger an additional surcharge when you file the final annual return.</p> <p>Some companies also have obligations related to specific business types or licences that fall quarterly, such as excise tax filings for businesses in applicable industries. If your business holds any special operating licences, it is worth confirming with your accountant whether sector-specific quarterly filings apply to you.</p> <h2>The Big Annual Deadlines Every Company Must Know</h2> <p>Beyond the monthly rhythm, there are three major annual filings that require serious preparation. The first is the annual corporate income tax return, form PND 50, which must be filed within 150 days of your accounting year end. For a December year end, that means the deadline falls around late May of the following year. This return is based on your audited financial statements, which means your accounts need to be finalised and audited before you can file. Starting the audit process early is strongly advisable.</p> <p>The second major annual obligation is the submission of audited financial statements to the Department of Business Development. This is separate from the Revenue Department filing and must be done within five months of your accounting year end, typically accompanied by a summary report of the annual general meeting of shareholders. The third is the annual personal income tax return for any individual directors or employees who earn income in Thailand, which is due by 31 March each year for the prior calendar year, or by 8 April if filing online.</p> <h2>Keeping Track: Practical Tips for Staying on Top of It All</h2> <p>The most common mistake new business owners make is treating compliance as something to think about only when a deadline has already arrived. By that point you are already under pressure, and errors are more likely. A simple approach that works well in practice is to maintain a shared calendar that shows every filing date for the year ahead, colour-coded by filing type. Your accountant should ideally be providing you with reminders ahead of each deadline, but having your own visibility means you are never caught off guard.</p> <p>It also helps to keep your bookkeeping current month by month rather than letting receipts and invoices pile up. Accurate monthly accounts make every filing faster and more reliable, and they mean your annual audit is not starting from scratch. For foreign business owners in particular, working with a local accounting firm that handles the filings on your behalf and communicates clearly in English removes a significant source of stress and reduces the risk of errors caused by language barriers or unfamiliarity with Thai Revenue Department procedures.</p>