LEI vs DUNS vs Registration Number vs EIN vs VAT Number: Which Business Identifier Do You Actually Need

Every company in the world has at least one identifier. Most have three or four. Some have a dozen. And if you work in compliance, procurement, or data operations, you already know the headache: which identifier do you use, when, and why?

This guide breaks down the five most common business identifiers — company registration numbers, DUNS numbers, LEIs, EINs, and VAT numbers. No jargon. No fluff. Just a clear answer to the question: which one do you actually need?

What Are Business Identifiers (And Why Do They Matter)?

A business identifier is a unique code assigned to a company by a government, regulatory body, or private organization. It exists so other entities — banks, regulators, suppliers, customers — can verify that a company is real, legally registered, and authorized to operate.

• The Problem With Multiple Identifiers
  Here is the core issue. There is no single, universal business identifier. Different identifiers were created by different organizations, at different times, for different purposes. A company registered in Germany will have a Handelsregisternummer (commercial register number). That same company might also hold a DUNS number for international procurement, an LEI for derivatives trading, and a VAT number for invoicing within the EU.
  For compliance teams running KYB (Know Your Business) checks, this creates a real problem. You cannot rely on one identifier to verify a company across all contexts. You need to know which identifier applies where — and how to cross-reference them.

• How Business Identifiers Impact KYB, Compliance, and Procurement
  Identifiers are not just administrative details. They drive decisions. A missing or unverifiable LEI can block a financial transaction. A DUNS number with a poor credit score can disqualify a supplier. An invalid VAT number can trigger tax penalties on a cross-border invoice.
  Understanding identifiers is not optional for enterprise teams. It is operational.

What Is a Company Registration Number?

A company registration number (CRN) is the most fundamental business identifier. It is assigned by a government registry when a business is legally incorporated. Every country has its own version.

In the UK, Companies House issues a CRN. In Germany, the Handelsregister issues the HRB number. In the US, each state’s Secretary of State issues a registration number. In Singapore, ACRA issues the UEN. The format, structure, and naming vary, but the purpose is the same: prove this company legally exists.

• How Company Registration Numbers Work by Country
  Registration numbers are tied to a specific jurisdiction. A UK CRN only proves incorporation in the UK. It tells you nothing about a company’s operations in other countries. For multinational entities, you often need registration numbers from multiple jurisdictions to build a full picture.
  The data attached to a registration number also varies. Some registries publish directors, shareholders, and financial statements. Others only confirm the company name and registered address. This inconsistency makes cross-border verification challenging.

• When You Need a Registration Number
  You need a registration number for entity verification during onboarding, opening bank accounts, signing contracts, filing regulatory paperwork, and proving legal existence to any counterparty. It is the starting point for any due diligence process.

What Is a DUNS Number?

A DUNS (Data Universal Numbering System) number is a nine-digit identifier issued by Dun & Bradstreet (D&B). Unlike registration numbers, DUNS is a proprietary system run by a private company. It was introduced in 1963 and now covers over 500 million business records across 190+ countries.

DUNS numbers are primarily used for business credit reporting and supplier evaluation. A company’s DUNS number links to its D&B credit profile, including payment history, financial stability scores, and corporate relationships.

• Who Issues DUNS Numbers and What They Cost
  D&B issues DUNS numbers for free at the basic level. However, accessing the credit data and analytics tied to a DUNS number requires a paid subscription to D&B’s products. This means the identifier itself is free, but the useful data behind it is behind a paywall.
  Organizations like the European Commission, the United Nations, and Apple require or recognize DUNS numbers for supplier registration and developer accounts.

• Why the US Government Stopped Using DUNS
  In April 2022, the US federal government officially replaced the DUNS number with the Unique Entity Identifier (UEI) through SAM.gov. The Government Accountability Office had found that relying on a proprietary identifier created higher costs, limited data access, and reduced competition. The UEI is now the standard for federal contracting and grants.
  Despite this, DUNS numbers remain widely used in the private sector for credit checks, procurement, and international supplier vetting.

What Is a Legal Entity Identifier (LEI)?

The Legal Entity Identifier (LEI) is a 20-character alphanumeric code that uniquely identifies legal entities participating in financial transactions. It was created after the 2008 financial crisis, when regulators realized they had no reliable way to trace counterparty relationships across global markets.

The LEI is managed by the Global Legal Entity Identifier Foundation (GLEIF), a nonprofit backed by the G20 and the Financial Stability Board. Over 300 regulations worldwide now require or recommend the use of LEI.

• How LEIs Work and Who Requires Them
  LEIs are issued by GLEIF-accredited Local Operating Units (LOUs). Unlike most identifiers, LEIs must be renewed annually, and the data is publicly accessible at no cost through the GLEIF database. Any entity involved in financial transactions — banks, investment firms, corporations trading derivatives, securities reporters — typically needs an LEI.
  Regulations like MiFID II in Europe and Dodd-Frank reporting in the US mandate LEI usage. The European Securities and Markets Authority (ESMA) requires LEIs for all entities reporting financial transactions.

• LEI and Corporate Ownership Data (Level 1 vs Level 2)
  What makes LEIs different from other identifiers is the ownership data. GLEIF distinguishes between Level 1 data (“who is who” — basic entity information) and Level 2 data (“who owns whom” — direct and ultimate parent relationships). This makes the LEI particularly useful for mapping corporate structures and identifying beneficial ownership chains.

What Is an EIN (Employer Identification Number)?

An Employer Identification Number (EIN) is a nine-digit number issued by the Internal Revenue Service (IRS) to US business entities. It functions as a federal tax ID, similar to how a Social Security Number identifies individuals.

Every US business that hires employees, operates as a corporation or partnership, files certain tax returns, or withholds taxes on non-wage income is required to have an EIN. The number is free, permanent, and assigned immediately through the IRS online application.

• EIN vs Tax ID vs TIN — What’s the Difference?
  These terms cause a lot of confusion. In the US, a Tax Identification Number (TIN) is the umbrella category. It includes Social Security Numbers (SSN) for individuals, Individual Taxpayer Identification Numbers (ITIN) for non-residents, and Employer Identification Numbers (EIN) for businesses. So every EIN is a TIN, but not every TIN is an EIN.

• When an EIN Alone Isn’t Enough
  An EIN only works within the US tax system. It does not verify a company’s legal existence (that is the state registration number). It does not provide credit data (that is DUNS). It does not satisfy financial regulatory requirements (that is LEI). For any cross-border activity, you will need additional identifiers.

What Is a VAT Number?

A Value Added Tax (VAT) number is an identifier issued by national tax authorities to businesses registered for VAT. In the EU, every business that exceeds the VAT registration threshold in its country must register and receive a VAT identification number.

VAT numbers follow a standard format: a two-letter country code followed by a series of digits (e.g., DE123456789 for Germany, GB123456789 for the UK). The EU’s VIES (VAT Information Exchange System) allows cross-border verification of VAT numbers within member states.

• How VAT Numbers Work Across the EU and UK
  Within the EU, VAT numbers are critical for intra-community trade. When a business in France invoices a business in the Netherlands, both parties need valid VAT numbers to apply the reverse charge mechanism and avoid double taxation. Post-Brexit, the UK operates its own VAT system, and UK VAT numbers are no longer verifiable through VIES.

• VAT Number vs Tax ID — Key Differences
  A VAT number is specifically for value-added tax purposes. A Tax ID (such as an EIN in the US or a Steuernummer in Germany) covers broader tax obligations including corporate income tax, payroll tax, and withholding tax. In many countries, businesses have both a general tax ID and a separate VAT number.

LEI vs DUNS vs Registration Number vs EIN vs VAT: Side-by-Side Comparison

Here is a direct comparison across the key dimensions that matter for compliance, procurement, and data teams.

Comparison by Use Case

• For KYB and entity verification: Company registration numbers are the gold standard. They prove legal existence at the source.

• For supplier credit assessment: DUNS numbers link to credit profiles and payment history.

• For financial regulatory compliance: LEIs are mandatory under MiFID II, EMIR, and Dodd-Frank reporting.

• For US tax reporting: EINs are required for all federal tax filings.

• For EU cross-border invoicing: VAT numbers enable the reverse charge mechanism and intra-community trade.

Which Business Identifier Do You Need? A Decision Matrix

• For KYB and Entity Verification
  Start with the company registration number from the relevant jurisdiction. It is the most authoritative proof that an entity legally exists. Cross-reference with an LEI if the entity operates in financial markets, and verify the VAT number if invoicing within the EU.

• For Regulatory Compliance and Financial Reporting
  An LEI is required for most financial regulatory filings. If the entity reports derivatives, securities, or trades on regulated markets, the LEI is non-negotiable. In the US, supplement with the EIN for tax-related filings.

• For Vendor Onboarding and Procurement
  DUNS numbers remain the standard for enterprise procurement. Many large organizations and government agencies outside the US still require DUNS for supplier registration. Pair it with the registration number for legal verification.

• For Cross-Border Due Diligence
  No single identifier works. Cross-border due diligence requires layering multiple identifiers: the local registration number for legal existence, LEI for ownership mapping, VAT for tax compliance, and DUNS for creditworthiness. The challenge is matching all of these to the same entity.

The Real Problem: No Single Identifier Covers Everything

Why Enterprises Use Multiple Identifiers

Each identifier was created by a different organization, at a different time, to solve a different problem. Registration numbers prove legal existence. DUNS tracks credit. LEIs map financial relationships. EINs handle US taxes. VAT numbers manage EU trade tax. None of them were designed to replace the others.

For enterprise teams managing data on thousands of counterparties across dozens of countries, this fragmentation creates real operational pain. Matching a company’s registration number in the UK to its LEI, DUNS, and VAT number requires access to multiple databases, each with different formats, coverage gaps, and access costs.

How to Resolve Identifiers Into a Single Company Profile

The most effective approach is to use a data platform that aggregates and cross-references all major identifiers against a single company record. Instead of querying five separate databases, you query one.

Global Database, for example, sources company data directly from over 400 government registries worldwide and maps registration numbers, DUNS numbers, LEIs, EINs, and VAT numbers to unified company profiles covering 600+ million entities. This means compliance teams can verify an entity’s legal existence, check its financial identifiers, confirm its tax registration, and map its ownership structure — all from a single lookup.

Rather than treating each identifier as a separate silo, Global Database acts as the resolution layer that connects them. For enterprise buyers evaluating data providers, this is the key question: does the platform resolve all five identifiers to one record, or does it force you to do the matching yourself?

Frequently Asked Questions

1. Is a DUNS Number the Same as a Company Registration Number?
   No. A DUNS number is issued by Dun & Bradstreet, a private company. A company registration number is issued by a government registry when a business is legally incorporated. They serve different purposes: DUNS tracks credit and business relationships, while a registration number proves legal existence.

2. Do I Need an LEI If I Already Have an EIN?
   It depends on your activities. An EIN is for US tax reporting. An LEI is required for financial regulatory filings such as derivatives reporting under MiFID II or Dodd-Frank. If your company participates in financial transactions on regulated markets, you likely need both.

3. Can a VAT Number Be Used for KYB Verification?
   A VAT number confirms that a company is registered for value-added tax, but it does not confirm legal incorporation or ownership structure. It can be one data point in a KYB check, but it should not be the sole identifier used for entity verification.

4. What Replaced the DUNS Number for US Government Contracts?
   The Unique Entity Identifier (UEI) replaced the DUNS number in April 2022 for all US federal contracting and grants through SAM.gov. The change was driven by concerns over cost, data access limitations, and the proprietary nature of the DUNS system.

5. How Do You Verify a Company Using Multiple Identifiers?
   The most reliable method is to use a business intelligence platform that cross-references identifiers against official government sources. Platforms like Global Database map registration numbers, DUNS, LEIs, EINs, and VAT numbers to a single company profile, eliminating manual cross-referencing.

6. What Is the Difference Between a VAT Number and an EIN?
   An EIN is a US-specific tax identifier issued by the IRS for federal tax purposes. A VAT number is issued by national tax authorities (primarily in Europe) specifically for value-added tax. They operate in different tax systems and are not interchangeable.

7. Do All Countries Require an LEI?
   Not all countries require LEIs for all businesses. However, over 300 regulations worldwide reference the LEI, and any entity involved in regulated financial transactions in the EU, US, UK, Canada, Australia, India, and many other jurisdictions will need one. The trend is toward broader adoption.

8. Is a DUNS Number Still Relevant After the US Government Switch to UEI?
   Yes. While the US federal government no longer uses DUNS for contracting, the DUNS number remains widely used in the private sector. Many multinational corporations, European institutions, and organizations like the United Nations and Apple still require DUNS numbers for supplier registration and credit assessment.

9. Can I Look Up a Company’s LEI for Free?
   Yes. The GLEIF database (search.gleif.org) is publicly accessible and free. You can search by company name, LEI code, or registration number. This transparency is by design — the LEI system was built to be an open, non-proprietary standard.

10. How Does Global Database Help With Business Identifier Verification?
    Global Database sources data directly from over 400 government registries and maps all major business identifiers — registration numbers, DUNS, LEI, EIN, and VAT — to unified company profiles. This allows compliance, risk, and procurement teams to verify entities across all identifiers in a single search, covering more than 600 million companies worldwide. Instead of checking five separate databases, you check one.