Corporate Number Check Digit Calculator

The Japanese Corporate Number was originally 12 digits long. However, after the introduction of the My Number system, to avoid conflicts, the corporate number was adjusted by adding a check digit at the beginning of the 12-digit base, forming a complete 13-digit corporate number.

Existing issues:

• Registration documents (corporate certificates) typically only show the 12-digit number
• The Japanese National Tax Agency official website only accepts complete 13-digit corporate numbers for queries
• The official site does not support fuzzy matching
• Users need to manually calculate the check digit to perform queries