RNOKPP / IPN Validator (Ukraine Tax ID)
Validate authenticity, structure, and checksum of Ukrainian RNOKPP / IPN numbers.
About Ukrainian RNOKPP Validation
This tool inspects the 10-digit RNOKPP string, validating length and confirming that the 10th digit matches the official State Tax Service weighted Modulo 11/10 algorithm.
Secure, real-time client-side validation performed entirely in browser memory.
RNOKPP Validation Algorithm
- Strip spaces and dashes, validating that the input contains exactly 10 decimal digits.
- Calculate weighted sum using weights [-1, 5, 7, 9, 4, 6, 10, 5, 7].
- Compute expected check digit via (Sum % 11) % 10.
- Compare with the 10th digit of the input document.