REGON
National Official Register of Business Entities in Poland.
Use this page for field meaning, local checksum math, examples, and integration notes. Official identity, registry, account, or tax status still belongs to the owning system.
Entity Summary
- Jurisdiction
- Poland (PL)
- Category
- Polish Business Statistical Registry Number
- Format
- 9 numeric digits
- Local signal
- Registry body, region hint, checksum
What is REGON?
REGON (Rejestr Gospodarki Narodowej)
The REGON (Polish: Krajowy Rejestr Urzędowy Podmiotów Gospodarki Narodowej, National Official Register of Business Entities) is a statistical identification registry in Poland.
Introduced in 1975, it is used by government agencies to gather and track statistical economic data on all registered businesses, civil partnerships, and public institutions operating in Poland.
Issuing Authority
The REGON registry is managed by the Central Statistical Office of Poland (Główny Urząd Statystyczny - GUS).
Visual Structure Breakdown
Standard REGON numbers consist of exactly 9 digits structured as:
[ R R ] [ S S S S S S ] [ C ]| Field | Positions | Description |
|---|---|---|
| RR | 1–2 | Region code (assigned by the local statistical office branch). |
| SSSSSS | 3–8 | Unique business serial code. |
| C | 9 | Control checksum digit. |
Modulo Checksum Details
The REGON checksum uses a weighted modulo 11 algorithm.
Multipliers
The first 8 digits are multiplied by corresponding weight constants:
| Digit Position | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
|---|---|---|---|---|---|---|---|---|
| Weight | 8 | 9 | 2 | 3 | 4 | 5 | 6 | 7 |
Calculation
Sum the multiplication products:
\[S = \sum_{i=1}^{8} (d_i \times w_i)\]
The remainder is calculated as:
\[R = S \pmod{11}\]
The control checksum digit \(C\) is computed as:
- If \(R < 10\), then \(C = R\)
- If \(R = 10\), then \(C = 0\)
Validation Examples
| Sample Input | Description | Status |
|---|---|---|
| 192598474 | Valid REGON — Standard valid Polish National Official Business Register (REGON) number. | ✓ Valid |
| 123456789 | Invalid Checksum — Fails the weighted modulo 11 checksum verification. | ✗ Invalid |
| 12345 | Too Short — Must be exactly 9 numeric digits. | ✗ Invalid |
Implementation Guidance
Developer Guidelines
When implementing REGON validation:
- Standard REGON numbers must be exactly 9 numeric digits.
- Regex:
/^\d{9}$/. - Handle modulo 10 checksum adjustment: If
sum % 11 === 10, the control digit is0. - Verify the first two digits represent a valid region code.
function validateREGON(regon) {
if (!/^\d{9}$/.test(regon)) return false;
const weights = [8, 9, 2, 3, 4, 5, 6, 7];
let sum = 0;
for (let i = 0; i < 8; i++) {
sum += parseInt(regon[i]) * weights[i];
}
let remainder = sum % 11;
const checksum = remainder === 10 ? 0 : remainder;
return checksum === parseInt(regon[8]);
}Frequently Asked Questions
Can a REGON number have 14 digits?
Yes. Polish entities with local branches in other regions receive a 14-digit REGON number. The first 9 digits represent the parent company, followed by 4 branch digits, and a final checksum digit calculated with different weights.
Is REGON mandatory for all companies?
Yes. Every registered business partnership, cooperative, and enterprise in Poland must hold a REGON code for statistical reporting.
Official Registry Sources
References
1. GUS - Central Statistical Office (Poland): Central registry database lookup portal. Official GUS portal.
2. Act of 29 June 1995 on Official Statistics: The legal statutory basis establishing the REGON register schema.