Enter a Hong Kong identity card number to check its format and check digit.
Enter a Hong Kong identity card number to check its format and check digit.
Output appears here...
Start by entering an HKID

Type a Hong Kong ID number or generate one to see the validation summary.

Normalized HKID
Prefix lettersUnknown prefix
Body digits
Check digit
Weighted sum
Quick rule summary
  • Basic format: Use one or two uppercase letters, six digits, and a final check digit (0-9 or A). Parentheses around the last digit are optional.
  • Prefix letters: Single-letter HKIDs treat the missing position as value 36; double-letter HKIDs use both letters directly in the calculation.
  • Check digit rule: Convert letters to numbers (A=10…Z=35, space=36), multiply them by weights from 9 to 1, and ensure the total modulo 11 is zero. A remainder of 1 results in a check digit of A.
Disclaimer
  • Do not enter real personal HKID numbers; use sample data only.
  • This tool is for educational reference and is not an official verification service.
  • Generated numbers must not be used for impersonation or unlawful purposes.
Hong Kong Identity Card Validator - Check HKID Format and Check Digit - Paji toolset