Polish Business Registry Number

REGON Generator

Generates REGON numbers with a correct check digit. Supports both the 9-digit variant (legal entities) and the 14-digit variant (local units).

Generated numbers pass checksum validation but are not assigned to any real entity. For testing purposes only.

How many numbers to generate?

REGON variant

About the REGON generator

Use cases

REGON numbers appear in business registration forms, ERP systems, and accounting software. During development and testing, you need valid, structurally correct numbers without exposing data from real companies. The 14-digit variant is relevant when testing branch or local unit handling.

How generation works

For 9-digit REGON, the generator picks 8 random digits and computes the check digit using the modulo 11 algorithm with weights [8, 9, 2, 3, 4, 5, 6, 7]. For 14-digit REGON, a valid 9-digit base is generated first, 4 additional digits are chosen at random, and the second check digit is computed with weights [2, 4, 8, 5, 0, 9, 7, 3, 6, 1, 2, 4, 8]. In both cases, a computed remainder of 10 yields a check digit of 0.

Important limitation

Generated REGON numbers are for testing only. They are not registered in the GUS REGON database and must not appear in statistical reports, business registrations, or official documents.

Generator API

Each generator is backed by a REST API endpoint. Send a GET request with optional parameters and get an array of structurally valid numbers in JSON format.

GET /api/v1/generate/regon?count=5 &digits=9

Host: polishdata.eu

// Response 200 OK

{

"data": [

{

"regon": "012100784",

"digits": 9

}

],

"count": 5,

"type": "regon"

}

Explore API docs