Thai National ID 13 Digits: Check It Yourself

The 13-digit Thai national ID has an understandable structure, including a “check digit” that verifies the whole number.

Structure of 13 Digits

• Digit 1: person type (1 = born in Thailand, 2 = born abroad, 3 = alien)
• Digits 2-5: province + district of birth registration
• Digits 6-12: personal serial number
• Digit 13: check digit

How the Check Digit Works

1. Multiply the first 12 digits by weights 13, 12, 11, … 2 (left to right)
2. Sum all products → divide by 11 → take the remainder
3. Subtract the remainder from 11 → check digit (use 0 if result is 10)

Important

• A passing checksum only means the format is valid — not that it belongs to a real person
• Never share your national ID number unnecessarily

Check Automatically

Use our ID Card Checker — verifies the checksum and explains each digit. Free, runs in your browser, nothing leaves your device.