The DUNS to UEI Transition: Key Information for Contractors

Why the Federal Government Replaced the DUNS Number

For decades, the federal government relied on the proprietary Data Universal Numbering System (DUNS) administered by Dun & Bradstreet ^[1]. This required the government to pay licensing fees to distribute or analyze entity data. In April 2022, the GSA officially completed the transition to the Unique Entity ID (UEI) to establish government ownership of registration data.

The UEI is a 12-character alphanumeric string generated directly by SAM.gov during registration. Unlike the DUNS, the UEI utilizes the Crockford Base32 character set, omitting the letters I and O to prevent character transcription errors ^[2][1].