What is a DUNS number and do you need one?

A DUNS number(Data Universal Numbering System) is a 9-digit ID assigned by Dun & Bradstreet to a specific business location. D&B has been maintaining these since 1963 — over 500 million DUNS numbers exist worldwide. It's the primary identifier for the business credit reporting system.

What does a DUNS number look like?

Nine digits, typically written with hyphens: 12-345-6789. The digits themselves are sequential — there's no encoded meaning. It's a persistent ID assigned to your business the first time D&B encounters it, and it stays the same for the life of the entity.

How is it different from an EIN?

They're both 9-digit IDs for your business, but issued by different systems for different purposes:

• EIN is issued by the IRS. Used for taxes, banking, and vendor verification. Every US business needs one to open a bank account or apply for credit.
• DUNS is issued by Dun & Bradstreet (a private company). Used for building and referencing your business credit file. Optional in the strictest legal sense, but effectively required if you want business credit.

Do you need a DUNS?

Yes, in practice, if any of these apply:

• You want to build business credit that vendors and lenders can see.
• You're applying to a Net-30 vendor that reports to D&B (Uline, Quill, Grainger, and most trades vendors).
• You're bidding on private-sector contracts over $250k (many require D&B verification).
• You're trying to open Net terms with a larger corporate customer.

Federal government contracting used to require a DUNS but shifted to the UEI in April 2022. See below for details.

DUNS vs UEI (federal government)

In April 2022, the US federal government replaced DUNS with the UEI (Unique Entity Identifier) — a 12-character alphanumeric ID issued for free through sam.gov. If you bid on federal contracts, you need a UEI, not a DUNS.

For everything else — private-sector business credit, vendor accounts, business credit cards — DUNS remains the standard. D&B is still the largest business credit bureau and their DUNS-based system is deeply embedded across the private sector.

How do you get a DUNS?

Free from D&B, ~30 business days for the standard path. See the full walkthrough: How to get a DUNS number for free.

What does having a DUNS unlock?

Vendor Net-30 accounts

Most D&B-reporting Net-30 vendors will open an account without a DUNS, but reporting is materially slower and less reliable without one. Once you have a DUNS, vendors like Uline and Grainger report your first paid invoice within 30-60 days.

Business credit card underwriting

Chase Ink cards, Amex business cards, and Capital One Spark cards all pull your D&B file as part of underwriting. Without a DUNS, they can only see your personal credit — which materially reduces both approval odds and starting credit limits.

Corporate onboarding

Corporations with over $1M in revenue often refuse to onboard a vendor without a DUNS. This is because their procurement systems (SAP, Oracle) use DUNS as the primary vendor key.

Trade credit references

When you apply for a new Net-30 line, the vendor asks for trade references. Providing a DUNS number lets them pull your D&B file directly, which is faster than calling each reference individually.

Common questions

Does having a DUNS affect my score?

No — having a DUNS by itself is neutral. It's just the ID. Your Paydex score comes from the payment history attached to it via reporting vendors.

Can I have multiple DUNS?

Yes — each legal entity gets its own DUNS. If you own three LLCs, you have three DUNS numbers.

What if my business info changes?

Update your DUNS profile through D&B iUpdate at dnb.com/duns/lookup. Change of address, phone number, or industry code should be reflected within 30 days.

Is a DUNS the same as a Business ID / State ID?

No. Your state assigns you a State Business Identification Number when you register with the Secretary of State — that's a separate ID used for state tax purposes. D&B's DUNS is a private-sector ID used for credit reporting.