Serial Number

A serial number uniquely identifies individual products within the same model. While lot numbers identify manufacturing groups, serial numbers distinguish each unit. They appear on warranty cards, software licenses, and luxury brand certificates.

The primary benefit of QR-encoded serial numbers is per-unit authentication. Luxury brands assign unique serial-numbered QR codes; consumers scan to verify authenticity against the manufacturer's database. Counterfeits carry unregistered serial numbers.

Advanced anti-counterfeiting combines serial numbers with digital signatures. Manufacturers sign serial numbers with private keys and embed the signature in QR codes. Verification apps check signatures with public keys, enabling offline authentication.

In GS1 standards, serial numbers use AI 21. A single GS1 QR code with GTIN + lot number + serial number enables product identification, lot tracking, and individual tracking in one scan. Pharmaceutical regulations increasingly mandate serialized QR codes on individual drug packages.