TEKLYNX Blog: The Human Readable

What Is a Check Digit? The Key to Barcode Accuracy & Validation

BY: TRAVIS WAYNE / DATE: 19/06/2025 / TOPICS: AUTOMOBILOVÝ PRŮMYSL, POTRAVINY A NÁPOJE, ZDRAVOTNICTVÍ, VÝROBA, ZDRAVOTNICKÉ PROSTŘEDKY, FARMACEUTICKÝ PRŮMYSL, MALOOBCHOD, ODESÍLÁNÍ A PŘÍJEM, SKLADOVÁNÍ A DISTRIBUCE, BARCODE BASICS, REGULATORY COMPLIANCE

What is a check digit? Simply put, a check digit is an extra number added to a barcode to help detect errors. Barcode check digits are calculated using algorithms during both barcode creation and scanning. If the scanned check digit matches the created check digit, the barcode was scanned correctly.

Check digits are foundational to barcode data integrity, validation, and quality. In this blog, we’ll dive into what check digits are, how they work, and why they’re important.