Japan Individual My Number Validator
Validate the authenticity, format, and checksum of Japan Individual My Number.
About Japan Individual My Number Validation
My Number (Individual Number / 個人番号) is the 12-digit social security and tax identification number in Japan.
Composed of 12 digits, where the 12th digit is calculated using the official weighted modulus formula defined by Japanese ministerial ordinance.
Anatomy & Structure of My Number (マイナンバー / Individual Number)
The Japanese Individual Number consists of 12 numeric digits in 2 parts:
| Position | Field | Length | Meaning & Rule | Example |
|---|---|---|---|---|
| 1 to 11 | Base Individual Number | 11 digits | Unique sequence assigned by J-LIS to residents in Japan | 12345678901 |
| 12 | Check Digit | 1 digit | Calculated via weighted Modulo 11 (MIC Ministerial Ordinance No. 85/2014) | 2 |
Official Algorithm (Weighted Modulo 11 — MIC No. 85/2014)
Official check digit calculation for Japan My Number:
S = Σ P[n] × Q[n]; R = S mod 11; DV = R <= 1 ? 0 : 11 - R
- 1. Number the first 11 digits from n=1 (rightmost) to n=11 (leftmost).
- 2. For 1 <= n <= 6, weight is Q[n] = n + 1 (weights: 2, 3, 4, 5, 6, 7).
- 3. For 7 <= n <= 11, weight is Q[n] = n - 5 (weights: 2, 3, 4, 5, 6).
- 4. Compute weighted sum S and remainder R = S mod 11.
- 5. If R is 0 or 1, check digit is 0; otherwise DV = 11 - R.