# DUNS Number Search

> Check the format of a D-U-N-S number and see where a nine-digit number comes from.

Canonical: https://corpoapi.com/checks/duns-number-search

Type a D-U-N-S number and the check reports whether it is nine digits. There is no public check digit, so the check reads the shape only and cannot tell you whether the number was issued. Dun and Bradstreet issues D-U-N-S numbers and is the place to confirm one.

## What the check reads

- **Nine digits** The count runs after spaces and hyphens are stripped, so 123 456 789 and 123-456-789 are the same input.

- **No check digit** A D-U-N-S number has no public check digit, so the check cannot test one. This is why the result confirms the shape only and does not call the number valid.

- **Letters rejected** The number is digits only. A string with a letter in it fails, because a D-U-N-S number contains none.

- **Length, not value** Any nine digits pass. The check has no way to tell a real number from a random one, and it does not try.

- **What this does not check** Whether the number was issued, which business holds it, and whether that business still trades. Dun and Bradstreet holds all of that.

## Where the data comes from

- [Dun and Bradstreet](https://www.dnb.com/): The issuer of the D-U-N-S number and the only source that confirms one.

## Worked examples

### Nine digits in the right shape

Input: `123456789`

- **D-U-N-S number**: 123456789

- **Format**: Nine digits

- **Check digit test**: None published

- **Verdict**: Well formed

This is a format example, not a real number. Dun and Bradstreet publishes no check digit, so the check cannot confirm the number exists.

### Spaces and hyphens are ignored

Input: `123 456 789`

- **Digits**: 9

- **Separators**: Ignored

- **Verdict**: Well formed

The number is often written in groups, so the check strips the separators before it counts.

### One digit short

Input: `12345678`

- **Digits**: 8

- **Needed**: 9

- **Verdict**: Not a D-U-N-S number

A dropped digit is the commonest mistake, and there is no check digit to catch it.

## Nine digits, and nothing to compute

A D-U-N-S number is nine digits. Unlike an LEI or a Swedish organisationsnummer, it carries no published check digit, so there is no arithmetic that can confirm a number. The check strips spaces and hyphens and counts the digits.

- Nine digits, spaces and hyphens ignored
- No check digit, because none is published
- Letters are rejected

## A nine-digit number is not a D-U-N-S number

Any nine digits pass. The check cannot tell an issued D-U-N-S number from a random nine-digit string, and it cannot name the business behind one. Dun and Bradstreet issues and holds D-U-N-S numbers, and it is the only place a number is confirmed.

- A valid shape does not prove the number is issued
- No source maps a D-U-N-S number to a company in the open
- The check never reaches Dun and Bradstreet

## Dun and Bradstreet holds the number

Dun and Bradstreet runs a lookup for a D-U-N-S number and the company record behind it. If all you have is a company name and address, that lookup finds the number. Our free company search is the register route, for the legal entity rather than the credit file.

- Confirm the number with Dun and Bradstreet
- Find the number from a name and address
- Use the free company search for the register record

## FAQ

### Does this find the company behind a D-U-N-S number?

No, and no public source we can read does. A D-U-N-S number is issued and held by Dun and Bradstreet and is not published against a company in any open register. Dun and Bradstreet's own lookup is the place to confirm a number.

### Does a valid nine-digit number prove the D-U-N-S exists?

No. A valid format means the input is nine digits, nothing more. The check cannot tell an issued number from a random one, so it never claims a number is valid.

### Why is there no check digit?

Dun and Bradstreet does not publish the arithmetic behind a D-U-N-S number, so no honest check can recompute one. The check reads the shape and says so.

### What is a D-U-N-S number used for?

It is a nine-digit identifier for a business, used in credit reports, supplier onboarding and procurement. It is not a government number and is not tied to a register.

### Is a D-U-N-S number the same as an EIN?

No. An EIN is the tax-side number the US tax authority issues. A D-U-N-S number is issued by Dun and Bradstreet for business identification. The two look alike but have no relation, and each has its own check on this site.

### Is the check free?

Yes. It is free and needs no account. The nine-digit rule runs in your browser, so retrying a mistyped number costs nothing, and each well-formed D-U-N-S number you check uses one of the tool's 5 daily checks.