What Is a DUNS Number? | DUNS vs UEI, EIN, NAICS, and SIC
What is a DUNS number? A D-U-N-S® Number is a unique 9-digit business identifier assigned by Dun & Bradstreet. It is used to identify business entities, connect location and corporate-family relationships, and support workflows such as supplier onboarding, credit reporting, and commercial due diligence.
For U.S. federal contracting, the key point today is this: SAM.gov’s Unique Entity ID (UEI) is now the official identifier for federal award purposes. DUNS still matters in commercial credit and vendor ecosystems, but it is no longer the federal award identifier.
Why People Look Up a DUNS Number
Most people researching DUNS have one of two goals: they either need to satisfy a vendor, procurement, or onboarding requirement, or they want to establish and maintain a recognizable business credit identity.
- Commercial identity and onboarding: supplier qualification, enterprise onboarding, international trade, and vendor review
- Business credit visibility: creating or maintaining a D&B-linked business credit profile
- Entity matching: helping large organizations connect a business to a stable third-party identifier
Business Identity Stack
Businesses often confuse EIN, UEI, DUNS, SIC, and NAICS. These are not interchangeable. They solve different problems and often work together in the same workflow.
Tax identity: issued by the IRS for federal tax reporting and payroll.
Common use: tax filings, payroll, banking, vendor forms requiring a tax ID.
Federal entity identity: the official identifier used in SAM.gov for U.S. federal award and entity registration workflows.
Common use: federal contracting, assistance, and SAM.gov-based entity records.
Commercial business identity: Dun & Bradstreet’s business identifier used to anchor D&B records and business-credit-related workflows.
Common use: supplier onboarding, commercial credit, third-party due diligence, and corporate linkage.
Industry classification: describes what your business primarily does using the North American classification standard.
Common use: reporting, market sizing, procurement alignment, analytics, and operational segmentation.
Legacy industry classification: still widely used in many private-sector databases, compliance workflows, and historical reporting systems.
Common use: segmentation, vendor databases, legacy alignment, and longitudinal comparability.
SICCODE.com focus: if you need to describe your business correctly for onboarding, contracts, or vendor review, choosing the correct NAICS and SIC codes is one of the highest-impact steps you can take before you submit profiles to third parties.
Identity Comparison Table
Use this quick reference when you are not sure which identifier or classification you actually need.
| Identifier | Issued by | What it identifies | Most common reason people need it |
|---|---|---|---|
| EIN | IRS | Your tax entity for federal reporting and payroll | Banking, payroll, tax filings |
| UEI | SAM.gov / U.S. Government | Your federal entity identity for government award workflows | Federal contracting, grants, SAM entity registration |
| DUNS | Dun & Bradstreet | Your D&B-linked commercial business identity | Commercial credit profile, supplier onboarding, third-party entity matching |
| NAICS / SIC | NAICS: U.S./Canada/Mexico standard; SIC: legacy U.S. standard | Your industry activity | Classification for bids, reporting, segmentation, and compliance |
DUNS, PAYDEX, and Business Credit
One of the most common reasons a small business wants a DUNS number is to build a recognizable D&B business credit profile. In practice, the DUNS number helps anchor your business within D&B’s commercial identity and credit environment.
- Why it matters: lenders, suppliers, and larger enterprises often want a stable third-party identifier tied to your business record
- What follows from that identity: payment history and related business credit indicators can be linked to the D&B file
- Why data consistency matters: your legal name, address, phone, website, and industry description should be consistent to reduce fragmented or duplicate records
Risk signal: your industry classification affects how outside parties interpret your business. If your business model changes, update your NAICS and SIC codes first, then update external profiles to reduce mismatch and confusion.
Federal Contracting Context
DUNS used to play a major role in federal registration workflows, but that changed. For U.S. federal award identification, the Unique Entity ID (UEI) from SAM.gov is now the official identifier. If your goal is federal contracting, you should think in terms of SAM registration and UEI first.
- SAM.gov: register your entity or request a UEI through SAM.gov for federal award workflows
- UEI, not DUNS: UEI is now the official federal identifier for doing business with the U.S. Government
- CAGE workflow: some contracting paths also involve a CAGE code after federal registration steps are completed
- Classification still matters: accurate NAICS and SIC support eligibility, reporting alignment, and clearer vendor records
Practical takeaway: if your use case is federal awards, do not treat DUNS as the current required identifier. Start with SAM.gov entity registration and UEI.
How to Get a DUNS Number
DUNS numbers are issued directly by Dun & Bradstreet for commercial identity workflows.
- Go to Dun & Bradstreet’s D-U-N-S Number page
- Submit your business information for review or lookup
- After verification, the D-U-N-S Number is assigned to the business record
If your actual goal is federal contracting rather than commercial identity, use SAM.gov to get a Unique Entity ID instead of starting with DUNS.
NAICS and SIC Classification Help Before You Submit Profiles
Many onboarding and registration workflows ask for NAICS and sometimes SIC because those codes describe your primary business activity. They are used to evaluate eligibility, segment vendors, and align reporting.
- Find your NAICS code: What is a NAICS Code?
- Find your SIC code: What is a SIC Code?
- Browse directories: NAICS Code Lookup Directory and SIC Code Lookup Directory
Best practice: confirm your NAICS and SIC selection before updating external profiles. Correct classification helps reduce downstream mismatches in vendor systems, credit files, onboarding reviews, and reporting workflows.
Managing Your D&B Profile
Data decay is one of the biggest causes of vendor delays, credit-profile confusion, and duplicate-entity problems. If your business changes, update records quickly and consistently.
- Moved locations: update address and phone information to reduce verification failures
- Changed your business model: recheck primary NAICS and SIC codes so your classification matches current operations
- Restructured or expanded: keep legal name, DBA, and entity structure aligned across systems
- Ongoing hygiene: maintain current websites, domains, contacts, and size indicators to reduce stale-entity flags
Frequently Asked Questions
- Is a DUNS number free?
Businesses can request a D-U-N-S Number through Dun & Bradstreet for commercial identity purposes, and D&B provides lookup and request options through its official pages. - Is a DUNS number the same as SAM registration?
No. A DUNS number is a D&B business identifier. SAM registration is a U.S. federal entity registration workflow that now uses the Unique Entity ID (UEI). - Do I still need NAICS and SIC codes?
Yes. DUNS or UEI identify the business entity. NAICS and SIC classify what the business does. - Can one company have multiple DUNS numbers?
Yes. Separate locations or legal entities can have distinct D&B records depending on how they are organized and verified. - What should I do if my business changes industry focus?
Confirm your updated NAICS and SIC codes first, then update external profiles so your classification matches your current operations.