UPC stands for Universal Product Code, which was the first system of bar code labelling to be widely adopted. According to BarCode 1, the American grocery industry first established UPC as the standard bar code symbology for product marking April 3, 1973, and foreign interest in UPC led to the adoption of the EAN code format, (a format similar to UPC), in December 1976.
In Canada, the Electronic Commerce Council of Canada (ECCC), a non-profit organization, maintains global standards for the identification of goods, and deals with bar code issuance and maintenance.
Businesses that offer products for sale using a brand name/label that belongs to them and businesses that trade outside of Canada need to have UPC bar codes. UPC bar codes are also handy for scanning and tracking your products through the supply chain.
If you need a UPC (a.k.a. bar code), you need to apply to the ECCC for membership and a company prefix. (The link will take you to the ECCC page with details about the UPC bar code application process.)
Any business that uses UPCs also needs to be aware that as of January 1, 2005, "all U.S. and Canadian companies must be capable of scanning and processing EAN-8 and EAN-13 symbols, in addition to 12 digit UPC symbols, at point of sale" (ECCC). The purpose of this Sunrise 2005 initiative is to ensure global conformity of the EAN/UCC numbering system (upon which UPCs are based) and make trade between countries easier. You may need to make system changes to comply.