Angola INSS Employer Number Validator
Online validator for Angola INSS Employer Registration Number (Contribuinte). Mathematical check digit (Modulo 11) verification.
About INSS Employer Validation
The Contribuinte Number at INSS Angola identifies corporate entities and employers within the social security framework. This validator checks the structural and mathematical authenticity of the ID.
Validation applies the official Modulo 11 checksum (weights 9 to 2), strictly rejecting corrupted check digits and repeated digit sequences.
Angola INSS Employer Number Structure
Breakdown of the 9-digit INSS employer identification code:
| Position | Field | Length | Meaning & Rule | Example |
|---|---|---|---|---|
| 1 and 2 | Registration Series | 2 digits | Employer registration prefix within the INSS registry | 00 |
| 3 to 8 | Sequential Registration | 6 digits | Sequential employer registration number assigned by the INSS | 123456 |
| 9 | Check Digit (DV) | 1 digit | Verification digit computed via Modulo 11 with weights 9 to 2 | 4 |
Check Digit Calculation (Modulo 11)
Mathematical algorithm defined by INSS Angola regulations:
Sum = Σ(digit[i] × weight[i]) for i from 0 to 7, with weights [9, 8, 7, 6, 5, 4, 3, 2]. Remainder = Sum % 11. If Remainder < 2, DV = 0; else DV = 11 - Remainder.
- 1. Multiply each of the first 8 digits by weights descending from 9 to 2.
- 2. Sum the products together.
- 3. Compute the remainder of dividing the sum by 11.
- 4. If remainder is 0 or 1, the check digit is 0. Otherwise, the check digit is 11 minus the remainder.