DUNS Number Definition | Business Credit Glossary

Definition

A unique nine-digit identifier assigned by Dun & Bradstreet to each business entity, used to anchor a business's credit file and identify it across D&B's global database.

Explanation

The Data Universal Numbering System (DUNS) number is a non-indicative identifier — it does not encode any information about the business itself, but serves purely as a unique key to link all of D&B's data about a specific business entity. Established in 1963, the DUNS system has become the de facto standard business identifier for commercial credit, government contracting, and supply chain management globally. When you register your business with D&B and obtain a DUNS number, D&B creates a business profile file in their database. All subsequent trade payment reports, financial records, and public data associated with your business are linked to this number. If your business has multiple locations, each location can have its own DUNS number, with the parent company having a separate "parent" DUNS that links the organization structure. The DUNS number is required for federal government contracts above certain thresholds — historically the SAM.gov registration (now using the Unique Entity Identifier or UEI) incorporated DUNS as part of the process. Many large corporations require DUNS numbers from their suppliers as a prerequisite for onboarding. Having a DUNS number signals that your business is established enough to be in D&B's database, which many procurement teams use as a basic legitimacy check.

Example

A construction subcontractor applies to be added to a general contractor's approved vendor list. The general contractor's procurement form requires a DUNS number, which the subcontractor obtains for free from dnb.com within a few days. This DUNS number allows the contractor to pull the subcontractor's D&B credit report and verify their payment history with other suppliers.

Why It Matters

Without a DUNS number, your business does not have a D&B file, which means lenders and suppliers who use D&B for credit decisions cannot pull a report on your business. This creates an information vacuum that many lenders fill by relying more heavily on your personal credit. Registering for a DUNS number is free and takes minutes — it is the foundational first step in building business credit with D&B.

Frequently asked questions

Does getting a DUNS number cost money?

Registering for a DUNS number is free at dnb.com. D&B does offer paid products — subscription monitoring services, enhanced business profiles, and access to other businesses' reports — but the DUNS registration itself costs nothing. Be aware of third-party websites that charge fees to register for a DUNS number on your behalf; these are unnecessary since you can register directly at no cost.