Unique Identification Codes for Federal Contractors: DUNS Numbers and CAGE Codes [November 21, 2016] [open pdf - 778KB]
"An essential element of the federal government's acquisition system is the capability to identify the businesses, and other types of entities, that do work for the government. Accurate identification of potential contractors and incumbent contractors facilitates a host of procurement processes while contributing to the transparency of federal government procurement. The federal government uses a proprietary system, Dun & Bradstreet's (D&B's) Data Universal Numbering System (DUNS), to uniquely identify the entities with which it does business. At no cost to the applicant, D&B assigns a DUNS number-a nine-digit unique identification code-to prospective government contractors. [...] Congress may have concerns regarding the continued use of DUNS numbers and has expressed interest in exploring other options. At the request of a Senate subcommittee, the Government Accountability Office (GAO) examined the costs and data restrictions involved with using a proprietary identification system and studied alternatives for identification numbers for government contractors."
CRS Report for Congress, R44490
Federation of American Scientists: http://www.fas.org/sgp/crs/index.html