D-U-N-S Number checker

Client

Vendor onboarding and government forms often list D-U-N-S Numbers beside LEI or tax identifiers. This page strips hyphens, confirms the nine-digit layout, and recomputes the published modulus‑10 check digit—pair with LEI checksum when the same counterparty row also has a Legal Entity Identifier.

What this checks

A D-U-N-S number is nine digits with a weighted mod-10 check on the body—used in vendor onboarding and credit files. A pass confirms layout and checksum math locally; it does not prove Dun & Bradstreet registration or legal entity status.

How to use in onboarding packs

Strip spaces and punctuation before validating. When the same spreadsheet lists payment rails or securities ids, cross-check LEI check, IBAN validate, and NAICS format in adjacent columns.

Privacy:checksum math runs locally in your tab. Toolcore does not query Dun & Bradstreet or business registries—format and check digit only.
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A D-U-N-S Number is 9 digits: eight data digits plus a modulus‑10 check digit with alternating weights 2,1,2,1 from the left. Hyphens in xx-xxx-xxxx grouping are stripped before validation.

Result

Vendor onboarding often lists D-U-N-S beside LEI—open LEI checksum when the same counterparty row also has a Legal Entity Identifier.

Passes D-U-N-S modulus‑10 check for 060704780.

Body (8)
06070478
Check digit
0

Nearby workflows on Toolcore

  • LEI check — when entity-level LEI codes sit beside D-U-N-S in KYC files.
  • IBAN validate — for payment identifiers in the same vendor onboarding row.
  • EIN format — for US tax ids that often appear with D-U-N-S in US onboarding.

Common use cases

  • Sanity-check a D-U-N-S copied from a supplier questionnaire before loading it into a procurement system.
  • Explain why a nine-digit DUNS fails mod‑10 while a related LEI on the same row still passes MOD‑97‑10.
  • Spot transposed digits in xx-xxx-xxxx grouping when only the DUNS column is available in legacy CSV feeds.
  • Contrast DUNS alternating 2,1 weights with standard Luhn on payment cards when finance teams mix identifiers.

Common mistakes to avoid

  • Treating a passing check as proof of business registration or creditworthiness

    Checksum validation confirms arithmetic only—not legal existence, sanctions status, or D&B credit scores.

  • Applying ISO Luhn (right-to-left doubling) to DUNS

    D-U-N-S uses alternating weights 2,1,2,1 from the left on the first eight digits, summing digits of products above nine.

  • Expecting Dun & Bradstreet company profiles

    Legal name, address, and hierarchy require D&B or licensed feeds—this page performs local format math only.

FAQ

Does Toolcore query Dun & Bradstreet?

No—the check digit and layout rules run entirely in your browser tab.

How is the D-U-N-S check digit calculated?

Multiply the first eight digits alternately by 2 and 1 from the left, sum digits of each product, then set the ninth digit so the total is divisible by 10.

Is D-U-N-S the same as a tax ID or LEI?

No—DUNS is a Dun & Bradstreet business identifier; tax IDs and LEI follow different formats and checksum rules.

Common search terms

Phrases people search for that match this tool. See the full long-tail keyword index.

  • duns number validator online
  • d-u-n-s check digit calculator browser
  • dun and bradstreet number checksum locally
  • validate duns mod 10 no directory lookup
  • nine digit duns format check free

More tools

Related utilities you can open in another tab—mostly client-side.