Guide

The D-U-N-S Number, in Plain Words

The D-U-N-S number is a nine-digit identifier Dun & Bradstreet assigns to a business. Its main job for a small business is simple: it is the key to your D&B business credit file. Supplier payments, public records, and other businesses' experiences get attached to that file. No number, no file — payments that could be building a record have nowhere to land.

What it costs

Nothing. A D-U-N-S number is free from Dun & Bradstreet. Third-party sites charge “expediting” fees to fill in the same request; before paying anyone, use the free route on D&B's own site. If a site implies the number itself carries a government fee, close the tab.

How long it takes

Plan on up to about 30 business days through the free route. That delay is an argument for requesting it early — in the first month of the business, alongside the EIN and the bank account — not for paying to skip a queue whose length nobody can promise you.

You may already have one

Businesses get assigned numbers without asking, sometimes when a vendor or lender reports on them. Use the free look-up on D&B's site before requesting a new one. If a listing already exists, read it carefully: an old listing under a former address or a slightly different name is exactly the kind of mismatch that screening systems trip on. Correct it to match your state record exactly.

D-U-N-S is not the UEI

Since 2022, businesses contracting with the federal government use the UEI (Unique Entity ID), issued free through SAM.gov. Government pages that mention D-U-N-S are describing history. The D-U-N-S still matters — for the business credit file. If your goal is selling to the government, you need the UEI; if your goal is a credit file that lenders can read, you need the D-U-N-S. Many businesses eventually hold both, for different reasons.

What a D-U-N-S does not do

It is an identifier, not a score and not a credential. It does not make a business creditworthy, and D&B sells monitoring products around the file that are separate decisions. Get the number, correct the listing, and then build the file the slow way: reporting tradelines, paid early, over real time.