Standards
D-U-N-S Number
A proprietary nine-digit identifier for a business location in Dun & Bradstreet data.
- Kind
- Identifiers
- Steward
- Dun & Bradstreet
- Official source
- https://www.dnb.com/duns-number.html
What it describes
The D-U-N-S Number is a Dun & Bradstreet identifier assigned to a business location. It appears in commercial reference data and older procurement records. The distinction between a location and a legal entity matters: multiple locations can have separate numbers, and a corporate hierarchy is additional reference data rather than something encoded in the nine digits.
For U.S. federal awards, the government replaced D-U-N-S with the Unique Entity ID generated in SAM.gov in April 2022. Historical records may still carry D-U-N-S numbers, so crosswalks require dated evidence. A number's presence in a vendor database does not alone establish current operating status, legal ownership, or eligibility for a government award.
Structure
Nine numeric digits.
Useful for
- Link historical supplier records.
- Reconcile business-location references.
- Maintain dated crosswalks to other entity IDs.
Limits
- Proprietary data and licence terms apply.
- A location is not necessarily one legal entity.
- No longer the U.S. federal award identifier.
How it is used in practice
The D-U-N-S Number has been the commercial identifier of record in credit files, supplier onboarding and procurement for many years. It is still the key that links a company to Dun & Bradstreet's hierarchy data, which describes parents, headquarters and branches. Many organizations hold D-U-N-S numbers in their vendor master files for reasons of history: contracts were signed, systems were integrated, and the number became part of the supplier record.
The change that matters for researchers is on the government side. Until April 2022, U.S. federal award systems used the D-U-N-S Number as the entity identifier. Since then, the Unique Entity ID generated in SAM.gov has taken that role. Records from before the transition carry D-U-N-S numbers, records after it carry UEIs, and a connection across the boundary requires a crosswalk.
A worked example
A fictional supplier, Halden Laboratory Services GmbH, appears in a 2019 purchase-order file with a D-U-N-S Number and in a 2024 federal award record with a UEI. The question is whether it is the same body. The numbers are in different systems, so they cannot be compared directly.
The researcher looks for a dated source that links them: the entity's SAM.gov registration, which in the transition period carried both identifiers, or a vendor-supplied crosswalk. If the registration shows both numbers for the same legal name and address, the link rests on that document and its date. If only a similar name connects the two, the link is a candidate, and the record keeps it as unresolved. The location-level nature of the D-U-N-S Number adds a second question: whether the 2019 number was that of the headquarters or of a branch, since a different location of the same company may carry a different number.
Evaluating a claim that rests on a D-U-N-S Number
The first check is whether the number names a location or a legal entity in the source. Commercial hierarchies assign numbers to sites and then link them. A claim about corporate ownership that rests on a site number needs the hierarchy data and its date, and that data is a proprietary product with its own terms.
The second check is currency. The status of a number, and the hierarchy it sits in, changes with mergers, relocations and closures. A number copied from an old supplier file is a historical fact about the file, not a statement about the company today. The third check is licence: much of the surrounding reference data is licensed, and a record should say which of its fields came from licensed material and under what restrictions, so that a later user knows what may be shown to whom.
Confusions to avoid
The D-U-N-S Number is not a legal-entity identifier. The LEI, a registry number or a tax number points to the legal person; the D-U-N-S Number points to a business location in a commercial database that also models relationships among locations. Two records with the same name and different D-U-N-S Numbers may be branches of one company or unrelated businesses, and the number alone cannot say which.
It is also not a credit rating or a mark of verification. Possessing a number shows that a business location has been recorded by the vendor, usually at the business's request or from public sources, and says little about the quality of the business. A procurement file that lists a number beside a supplier name should be read as a reference, and the claim that the supplier is real, active or financially sound needs its own evidence.
Questions a reviewer can ask
Does the number refer to a headquarters, a branch or a single location in the source? Which hierarchy, if any, was used to link it to a parent, and what is its date? Is the number current, or is it taken from an archived file? What licence applies to the vendor data that was used? If the claim spans the 2022 federal transition, which dated document links the number to the new identifier? Which of these facts were verified, and which were assumed?
Related terms
Found an error on this page? See corrections for what counts as one, how to report it and the dated log.
Enquiry
Which of your sources carry D-U-N-S Number?
Tell us which sources carry it, which key the same entity some other way and who may read which. We reply with whether and how a first record would use this identifier.
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