What this REGON validator does
This tool normalizes a REGON number, checks whether it has 9 or 14 digits, validates the checksum and shows a simple technical breakdown for the main entity part and local unit part where relevant.
Validation result
Enter a 9-digit or 14-digit REGON number to check the format and checksum.
This tool checks only REGON format and checksum. It does not query the official REGON register.
It does not confirm that an entity exists, is active, suspended, deleted or correctly registered.
For official registry data, users must use official Polish public registers.
How to use it
Paste the REGON with or without spaces or hyphens, then run the validation. Review the normalized number, detected format and checksum result before using the output elsewhere.
9-digit and 14-digit REGON format
A 9-digit REGON is usually the main entity number. A 14-digit REGON adds a local unit section after the first nine digits and ends with its own check digit.
REGON checksum algorithm
For 9-digit REGON the validator uses the weights 8, 9, 2, 3, 4, 5, 6, 7. For 14-digit REGON it uses 2, 4, 8, 5, 0, 9, 7, 3, 6, 1, 2, 4, 8. In both cases, if the calculated value is 10, it is replaced with 0.
Practical guidance
What this tool cannot verify
A technically valid REGON can still be unrelated to the entity you expect, inactive, suspended, deleted or otherwise unsuitable for a real-world process. This page does not query the official REGON register or any public registry service.
Limitations
The validator only checks format and checksum. It does not confirm that the entity exists, operates legally, has a specific address or should be trusted for tax, payroll, accounting or contract work.
Privacy note
The input is processed locally in your browser for the core validation result. The tool does not require an account and does not send the REGON to an API or official register lookup.
Last updated
Last updated: June 2026.
FAQ
Does a valid REGON confirm that the entity exists?
No. The validator checks only technical structure and checksum. It does not prove that the entity exists, is active or matches the record you expect in the official register.
What is the difference between 9-digit and 14-digit REGON?
The 9-digit version is typically the main entity number. The 14-digit version adds a local unit section after the first nine digits and has its own separate check digit for the full number.
Does this page query the official REGON database?
No. The page works locally in the browser and does not connect to the official REGON register. For official information you must use the proper Polish public registry tools.
Why can a technically valid REGON still be unusable?
Because checksum validation does not confirm registry status, current activity or ownership. A number can match the technical rule and still be suspended, deleted or unrelated to the entity you wanted to check.
Related tools
You may also want to check these local validators and related work tools:
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