Essential Fields for Thai Invoice Compliance
To ensure your Thai invoices are compliant, they must include specific mandatory information as stipulated by the Revenue Department. Every full format tax invoice needs to prominently display the words "Tax Invoice". Key details required are the seller's and buyer's full names, addresses, and their respective Tax Identification Numbers (TINs). For businesses, the TIN is a 13-digit number. Additionally, you must specify whether the entity is a Head Office or a Branch, including the 4 or 5-digit Branch ID (with "0000" or "00000" typically representing the head office). The invoice must also clearly state the issue date, a unique serial number, a detailed description of goods or services (quantity, unit price, and total value), and the Value Added Tax (VAT) amount, separated from the goods/services value. While not strictly mandated as "DD/MM/YYYY", using a consistent date format is crucial for clarity and record-keeping.