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DUNS Definition

The Data Universal Numbering System. A proprietary nine-digit identifier owned and administered by Dun & Bradstreet, previously used as the master contractor ID for federal procurement.

Federal Contracting Identifiers Comparison

Specification	Unique Entity ID (UEI)	DUNS Number (Retired)	CAGE Code
Length & Format	12 Alphanumeric (Crockford Base32)	9 Numeric	5 Alphanumeric
Authority	U.S. General Services Admin (GSA)	Dun & Bradstreet	U.S. Defense Logistics Agency (DLA)
Required For	All SAM.gov Prime awards & grants	Retired for federal use (April 2022)	Defense acquisitions & facility clearance
Registry Cost	Free of charge	Free (retired) / Commercial fees	Free of charge

💡 Expert Guidance

Common Mistake: Many federal contractors mistakenly assume they still need a D&B DUNS number to bid on federal solicitations. The DUNS number was retired in April 2022. Today, GSA systems only recognize the Unique Entity ID (UEI) generated inside SAM.gov. Do not pay third-party companies to purchase a DUNS number for federal compliance.

Frequently Asked Questions

What is the official definition of DUNS in compliance registry records? ▾

The term 'DUNS' is defined in compliance registers as: The Data Universal Numbering System. A proprietary nine-digit identifier owned and administered by Dun & Bradstreet, previously used as the master contractor ID for federal procurement. This concept forms a primary component of corporate entity resolution and industry classification frameworks.

Which governing authority is responsible for publishing and maintaining the DUNS standard? ▾

The standard for DUNS is published, validated, and maintained under the direct oversight of an official regulatory body. They verify updates and publish the official registers for compliance audits.

What is the standard format and character length used for DUNS entries? ▾

The standard format for DUNS is structured as standard alphanumeric formatting. This specific layout guarantees formatting uniformity and prevents collisions in corporate databases.

How is DUNS utilized during regulatory compliance and entity registration? ▾

Organizations utilize DUNS during compliance verification and entity registration. Having a verified identifier is essential to transact with government bodies and complete bank KYC reviews.

Are there mathematical checks or checksum algorithms associated with DUNS codes? ▾

Many corporate identifiers associated with DUNS utilize mathematical checks (such as the ISO 7064 Mod 97-10 check digit routine or the omission of confusing characters) to detect transcription errors during manual entries.

Does an organization's DUNS identifier expire or require periodic renewal? ▾

Depending on the specific registry, identifiers associated with DUNS require annual renewal (e.g. keeping SAM.gov active every 12 months, or renewing LEIs with an LOU) to ensure the registry data remains accurate.

Can a business have more than one DUNS code assigned to it? ▾

For entity registrations or classification standards like DUNS, a business typically has a single primary identifier or code. For secondary classifications, a business can list multiple additional DUNS codes depending on the registry rules.

Is obtaining a DUNS identifier free or are there registration fees? ▾

Whether obtaining a DUNS identifier or standard is free depends on the registry. Federal identifiers (such as SAM.gov UEIs and CAGE codes) are completely free to obtain. However, international standards like the LEI require paying registration and annual renewal fees to the issuing LOU.

How can an auditor or compliance officer verify the status of a DUNS entry? ▾

A compliance officer can verify the status of a DUNS entry by querying the official registry database (such as the GLEIF index, SAM.gov public search, or the DLA portal) or by using the instant lookup tools on our site.

Is the DUNS classification standard uniform across all states in the U.S.? ▾

Yes, standard guidelines governed by federal or international agencies for DUNS are uniform nationwide, ensuring consistent compliance verification across all jurisdictions.

Related Guides & Tools

U.S. Federal Contracting Identifiers: DUNS, UEI, and CAGE Guide — A comprehensive reference detailing the required structural identifiers needed to transact with the U.S. federal government.
The DUNS to UEI Transition: Key Information for Contractors — Explains the transition from the proprietary D&B DUNS identifier to the GSA-owned Unique Entity Identifier (UEI) on SAM.gov.
LEI vs. DUNS vs. EIN: Understanding Corporate Identifiers — Compares global financial IDs (LEI) against commercial credit markers (DUNS) and IRS tax registrations (EIN).
SIC ↔ NAICS Concordance Crosswalk — Search and map old SIC codes to modern formats.