What is a DUNS number?
A nine-digit business identifier issued by Dun & Bradstreet, used globally for credit reporting, government contracting, and supply chain verification.
Also known as: DUNS, D-U-N-S Number
The DUNS Number (Data Universal Numbering System) is Dun & Bradstreet's global business ID. Unlike the EIN (US-only, IRS-issued), DUNS covers every country and is structured to identify legal entities and their corporate hierarchies (parent, subsidiary, branch). It is free to register, even if D&B's upsells make it feel otherwise.
DUNS is a hard requirement in two big areas. The US federal government uses it for contractor registration in SAM.gov (officially replaced by UEI in 2022, but DUNS is still widely referenced). Apple requires a DUNS to publish a paid app to the App Store under a company name. Many supply-chain compliance systems and credit-reporting services key off DUNS.
For brand-data work, DUNS is the most useful identifier when you need to tie a global counterparty to financial information (D&B credit scores, hierarchy data, payment behavior). Context.dev surfaces DUNS where available alongside EIN, NAICS, and address as part of company enrichment.
In the wild
- A US government contractor registering for a SAM.gov account using a DUNS number
- A supplier-onboarding workflow looking up a vendor's DUNS to pull D&B's credit risk score
- An app developer registering a company DUNS so their iOS app can publish under their company's name rather than a personal name