A DUNS Number is a nine-digit business identifier issued by Dun & Bradstreet. That's the short answer.
The more useful answer is this: if you came here trying to find decision-makers at companies, build a target account list, or enrich your CRM, this isn't the page you needed. A DUNS Number is a business-credit identifier. It isn't a sales prospecting tool. The conflation wastes a surprising amount of evaluation time.
Here's what a DUNS Number actually is, the small set of cases where you need one, and what to use instead if you're trying to solve a sales or marketing problem.
What is a DUNS Number?
DUNS stands for Data Universal Numbering System.
It's a nine-digit identifier assigned by Dun & Bradstreet, the credit-reporting firm that's been classifying businesses since 1841. Each physical business location gets its own DUNS, so a large company with 40 offices has 40 DUNS Numbers, all linked through D&B's corporate hierarchy data.
The DUNS itself is just a key. What lives behind the key, in the Dun & Bradstreet Data Cloud, is firmographic and credit data: industry classification, employee count, annual revenue, ownership structure, payment-history scores. D&B issues DUNS Numbers for free, but accessing the data behind them is what their business sells.
The number is mandated for some specific things like KYC/AML compliance in financial services, vendor onboarding at large regulated enterprises, and some commercial supplier portals. Outside those contexts, the DUNS Number is rarely doing useful work in a modern revenue stack.
When you need a DUNS Number
Be honest about whether either of these is you:
You operate in a regulated industry like banking, insurance, defense contracting, or healthcare where compliance requires a third-party business identifier. Your legal and compliance team will tell you which identifier they accept.
A commercial contract requires it. Some large enterprise procurement teams and supplier-onboarding portals still mandate a DUNS Number as part of vendor registration. If you're being asked for one to close a deal, you need it.
If neither of those describes you, keep reading.
Four problems a DUNS Number won't solve
If any of these sound like the problem you're trying to solve, you need a different tool.
1. 'I need to find companies to sell to'
The DUNS Number won't help you. What you need is a B2B prospecting database, a tool that lets you filter the universe of businesses by industry, employee count, technology stack, funding stage, location, and intent signals, then surface the right buyers at those companies. ZoomInfo, Apollo and Cognism are some of the most established options in this category. The DUNS Number can appear as a downstream field inside some of these tools, but it's never the input.
Concretely: if your task is "find me 500 mid-market US software companies whose marketing leader is hiring SDRs right now," the DUNS Number doesn't get you there. A prospecting database with filters across firmographics, technographics, and intent signals does.
2. 'I need to clean up my CRM data'
You need data enrichment, not a DUNS Number.
Enrichment tools take what you have in Salesforce or HubSpot, meaning names, emails, company names, and partial fields, and fill in the gaps from a continuously updated reference dataset. The output is a CRM where every account has current employee count, revenue range, industry, tech stack, and verified contact details on its key people. The DUNS Number might be one field in that output. It's not the deliverable.
3. 'I need to score leads and prioritize accounts'
You need firmographic data joined to intent data, joined to reasoning. Lead scoring works when you can combine "this company looks like our ICP" (firmographic fit) with "this company is in-market right now" (intent signals), and then a system that weights which combinations actually predict closed-won for your specific business. A DUNS Number is a static identifier. Lead scoring requires the opposite: signals that change daily.
4. 'I need to match accounts across systems'
You need an account-match engine. The problem of recognizing the same company across the marketing automation tool, the CRM, the data warehouse, and an inbound web form is solved by a match service that takes noisy inputs and returns a canonical company ID. The DUNS can be one of those IDs, but most modern stacks use a provider-specific ID instead. Provider IDs are available without licensing D&B data, easier to populate, and refreshed continuously.
See the Salesforce DUNS Number walkthrough for the longer version of this trade-off.
What you actually need (and what ZoomInfo brings to it)
All four of those problems share a solution: a B2B prospecting and intelligence platform. Here's what that looks like, and where ZoomInfo fits:
A searchable database of companies and contacts
ZoomInfo's data covers 500M+ professional profiles, 100M+ company records, 300M+ verified business emails, and 135M+ direct dial numbers
Filterable across hundreds of company and contact attributes including industry, size, revenue, location, hiring activity, tech stack, funding, and intent topics
96% email deliverability and 87% mobile-number accuracy, maintained by continuous AI verification and human research, with 1.5B+ data points processed daily
Native intent and signal data
ZoomInfo Intent tracks 4,500+ intent topics across 85M+ weekly signals, surfacing accounts actively researching your category before they raise their hand
Forrester named ZoomInfo a Leader in the 2025 Wave for Intent Data Providers, with the highest possible score across eight criteria including identity resolution, insight generation, and data integration
Guided Intent, exclusive to ZoomInfo, identifies topics historically correlated with deal success rather than requiring manual topic selection
CRM integration and enrichment, included
The ZoomInfo Sales product ships with native integrations into Salesforce, HubSpot, Marketo, Outreach, Salesloft, and Microsoft Dynamics. Enrichment runs as a continuous service rather than a one-time export, so the records in your CRM stay current as the underlying data changes.
An intelligence layer, not just a database
ZoomInfo's GTM Context Graph fuses third-party data with your CRM records, conversation transcripts from Chorus, and behavioral signals into a single graph. The graph captures the why behind a deal, not just the what. That's the difference between a static identifier like a DUNS Number and a system designed to reason about which accounts to engage and when.
D&B's own Hoovers product competes in the prospecting category, though it's the firmographic-led part of D&B rather than the credit business that issues the DUNS.
How to get a DUNS Number (if you actually need one)
The application is free and lives on D&B's website. You'll need legal business name, address, business structure, year founded, and the name of the person registering.
Standard processing takes anywhere from a few days to a few weeks depending on D&B's verification queue, and there's a paid expedited option if you need it faster.
D&B will try to upsell you various credit and monitoring products along the way. You don't need any of them for the DUNS itself.
Next step
If you came here trying to find target accounts, enrich your CRM, or build a prospecting workflow — that's what ZoomInfo does.
Book a walkthrough and see the database, intent signals, and CRM integration against your own ICP.
Frequently asked questions
Is a DUNS Number the same as a Tax ID or EIN?
No. EIN is issued by the IRS for tax purposes. DUNS is issued by D&B for business identification, primarily in the context of credit and corporate hierarchy. They're separate identifiers, issued by different entities, for different jobs.
Do I need a DUNS Number to use ZoomInfo or another B2B prospecting tool?
No. Prospecting tools don't require you, the buyer, to have a DUNS. The companies you're prospecting may have one, and that DUNS may appear as a field in the data you license — but it's not a prerequisite for the tool.
Is a DUNS Number free?
Yes, the number is free from D&B. Accessing the firmographic and credit data behind the number is the part that costs money, and that's what D&B sells.
How long does it take to get a DUNS Number?
Standard processing takes anywhere from a few days to a few weeks, depending on D&B's verification queue. D&B offers a paid expedited option for cases where you need it faster.
Does a DUNS Number affect my business credit score?
Not directly. The DUNS is an identifier. Your business credit profile (PAYDEX score and related metrics) is what changes as you pay vendors, take on debt, and build a payment history that D&B tracks against your DUNS.
What replaced the DUNS Number for federal contracting?
The Unique Entity Identifier (UEI), introduced by SAM.gov in 2022. UEI is now the primary identifier for federal contracting, though the DUNS often still appears alongside it during transition.
