A practical guide to PND 51, Thailand's half-year corporate income tax return: who must file, how to calculate the estimate, the 2026 deadlines, and how to avoid the 20% underestimation surcharge.

A practical guide to PND 90 and PND 91 in Thailand: who needs to file, which form to use, key deductions and allowances for 2025, and what changed for foreign income since January 2024.

Thailand's BOI now requires promoted companies to submit quarterly progress reports within 30 days of each quarter end. Here is what changed and what to action.

A practical overview of the five types of income tax in Thailand, what PND stands for, and which forms apply to individuals and companies.

A practical guide to the main legal structures, registration steps and requirements for international companies and foreign investors setting up in Thailand.