Polish PESEL Validator
ValidatorValidate a Polish PESEL number instantly and decode the birth date, sex, and current age it encodes. Confirms the weighted check digit. Free, runs in your browser.
Validating a company instead of a person?
PESEL identifies individuals. Poland's tax ID for businesses and taxpayers is the NIP. Try our NIP Validator →
About this tool
About Polish PESEL Validator
PESEL is Poland's 11-digit universal identification number. It encodes far more than a random ID: the first 6 digits are a birth date with a century-offset month field, the 10th digit's parity is the person's sex, and the 11th digit is a weighted check digit — making PESEL one of the richest 'decodable' IDs this site validates, in the same spirit as CURP.
Paste a PESEL and the tool verifies the weighted check digit, then decodes the real birth date (undoing the century offset on the month field), the sex, and the person's current age, all computed live from your device's clock.
Use this to verify a PESEL collected on a Polish-facing form, to understand what a PESEL actually encodes, or to double check a birth date or sex a PESEL implies before relying on it.
Instant, fully client-side validation and decoding with no data sent anywhere — useful both as a checksum validator and as a quick birth-date/sex/age decoder.
Key Features
- Verifies the PESEL weighted check digit
- Decodes birth date across all 5 supported centuries (1800s-2200s)
- Decodes sex from the serial's parity
- Computes current age live
- 100% browser-based, no data sent
FAQ
Polish PESEL Validator — Frequently Asked Questions
What does a PESEL actually encode?
The first 6 digits are a birth date (year, month, day), where the month is shifted by a century-specific offset (+0 for the 1900s, +20 for the 2000s, +40 for the 2100s, +60 for the 2200s, +80 for the 1800s). The next 4 digits are a serial number, whose last digit's parity (odd/even) encodes sex. The 11th digit is a weighted check digit.
Why does the month look like it's over 12?
That's the century offset at work. A month value like 25 doesn't mean month 25 — subtract 20 to get month 5, and the +20 itself tells you the person was born in the 2000s rather than the 1900s.
How is the age calculated?
It's computed live from the decoded birth date and your device's current date and time — the same whole-years-old calculation used elsewhere on this site (like the age calculator), not something baked into the PESEL number itself.
Can this tool confirm a PESEL belongs to a real, living person?
No. This is a mathematical structure and checksum check only. Confirming a PESEL is currently registered to a real person requires access to Poland's PESEL register, which this site cannot query.
Tips
- Spaces and hyphens are stripped automatically before validation
- The decoded age updates based on your device's current date
- Use the PESEL Generator on this site to create valid test numbers with a chosen birth date and sex
- NIP is Poland's separate tax ID for businesses, not individuals
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