UPC-A is the retail standard for product identification in the United States and Canada. Enter 11 digits and the check digit is appended automatically.
Structure
The 12-digit code consists of a 1-digit number system character, a 5-digit manufacturer code assigned by GS1-US, a 5-digit item reference, and a Modulo-10 check digit. GS1-US assigns the manufacturer segment.
Relation to EAN-13
UPC-A is a subset of EAN-13. A UPC-A value with a 0 prepended becomes a valid 13-digit EAN. International scanners typically accept both without distinction.