Thai National ID Validator
This free validator checks whether a 13-digit Thai national ID or taxpayer identification number is well-formed. It strips any spaces or dashes, verifies the official checksum digit, and tells you instantly whether the number is valid. It also decodes what the leading digit reveals about the ID category. Everything runs in your browser — no number is ever uploaded or stored.
Enter a 13-digit Thai national ID or 13-digit tax ID. Spaces and dashes are ignored.
The "Generate test ID" button creates a random checksum-valid number for form testing only. It is dummy data — it belongs to no real person or company.
Validation results will appear here
Enter a 13-digit Thai ID to check its checksum instantly.
Check digit:
What the leading digit means
The same checksum formula applies to both the 13-digit national ID and the 13-digit taxpayer / juristic (company) ID.
How to use
- Type or paste a 13-digit Thai ID or tax ID — spaces and dashes are fine.
- Read the instant verdict: a green "Valid" or red "Invalid" badge.
- Check the computed check digit and the standard 1-2345-67890-12-3 formatting.
- See what the leading digit says about the ID category.
- Use "Generate test ID" to create dummy, checksum-valid data for form testing.
Features
- Validates both the national ID and the 13-digit taxpayer / juristic ID
- Live checksum validation using the official mod-11 formula
- Decodes the leading digit into its person or entity category
- Accepts spaces and dashes and shows the standard grouped format
- Generates checksum-valid dummy IDs clearly labelled for testing only
- 100% in-browser — the number never leaves your device