The quick answer on which identifier you need
If your company operates internationally, applies for credit, files taxes, or trades financial instruments, you’ve probably run into an alphabet soup of identifiers: LEI, ISIN, DUNS, EIN, UEI, GIIN, VAT number, company registration number. They show up on the same forms. They sound alike. More than one accountant has mistakenly sent a bank a DUNS number instead of an LEI code. In reality these are eight completely different systems that happen to all be numbers or alphanumeric codes next to your company’s name.
Most businesses don’t pick one identifier over another. They accumulate several over time, because each one unlocks a different system:
| Identifier | Issued by | Format | Main purpose | Who typically needs it |
|---|---|---|---|---|
| Company registration number | National business registry | Varies by country | Proves legal existence and incorporation | Every registered company |
| VAT number | National tax authority | Country code + digits (e.g. DE123456789) |
VAT compliance, cross-border invoicing | Businesses trading VAT-taxable goods/services |
| EIN | US tax authority (IRS) | 9 digits (XX-XXXXXXX) |
US federal tax identifier | Businesses that operate or file taxes in the US |
| DUNS number | Dun & Bradstreet (private company) | 9 digits | Credit assessment, supplier/vendor checks | Businesses in procurement, credit checks |
| UEI | US government, via SAM.gov | 12-character alphanumeric code | US federal contracting and grants identifier | Businesses that do business with the US federal government |
| GIIN | US tax authority (IRS) | 19-character code (e.g. XXXXXX.XXXXX.XX.XXX) |
Proof of FATCA reporting compliance | Foreign financial institutions and funds reporting to the US on foreign accounts |
| ISIN | National numbering agencies (coordinated by ANNA) | 12-character alphanumeric code (ISO 6166) | Identifies a specific security, not a company | The issuer of the security |
| LEI | GLEIF-accredited LEI issuers | 20-character alphanumeric code (ISO 17442) | Global legal entity identification for financial transactions and ownership structure | Companies trading securities, derivatives, or otherwise subject to financial regulation |
If the table already answered your question, good. If you want to understand why these systems exist separately, keep reading.
What a company registration number is, and why it doesn’t replace an LEI
A national business registry issues a company registration number the moment a company forms legally, and it proves the company exists. A bank or partner usually checks it first. But it’s only reliable within its own jurisdiction.
Germany’s Handelsregister issues it. The UK’s Companies House issues it. In the US, it comes from the relevant state’s Secretary of State. The problem shows up once you cross a border. A German Handelsregisternummer means nothing to a Japanese counterparty without extra explanation, and no global system ties these different national numbers together. That’s exactly the gap the LEI (Legal Entity Identifier) fills, more on that at the end of this article.
What a VAT number is, and when you need one
A VAT number (Value Added Tax number) proves a company registered for VAT, and it determines how cross-border sales get taxed. Without a valid number, you can’t zero-rate an intra-EU transaction. Getting the treatment wrong is a common and expensive mistake.
A national tax authority issues the number. Within the EU it usually takes the form of a country code plus digits, for example DE123456789 in Germany. You can check validity through the European Commission’s VIES (VAT Information Exchange System), which is free and public. If you sell goods or services into another member state, your counterparty will likely ask for this number first.
What an EIN is, and whether companies outside the US need one
The US tax authority, the IRS (Internal Revenue Service), exclusively issues EINs (Employer Identification Numbers), 9-digit tax identifiers. Any company that pays US taxes, hires US employees, or opens a US bank account needs one. Outside the American tax system, an EIN means nothing.
Here’s where people commonly get confused. An EIN doesn’t prove a company is legitimate, and it says nothing about creditworthiness. It’s an accounting label for the IRS, nothing more. If your French company signs a contract with a US client who pays you from the US, your counterparty will likely ask for an EIN on a tax form, even if you’re never physically in the US.
What a DUNS number is, and whether the US government still uses it
Dun & Bradstreet, not any government, issues the DUNS number (Data Universal Numbering System), a 9-digit code used mainly for credit assessment and supplier checks. No, the US federal government no longer uses it for its own procurement. It switched to its own UEI system in 2022, more on that in a moment.
That said, DUNS stays in daily use across the private sector. If you bid on an international tender, or a potential client runs a supplier background check, chances are your counterparty will ask for this number, not your LEI code.
What a UEI is, and when it replaces a DUNS number
The US government issues a UEI (Unique Entity ID) directly through SAM.gov (System for Award Management). It’s a 12-character alphanumeric code. Since 2022, the US federal government has required it from anyone entering federal contracts or applying for federal grants, and it fully replaced the DUNS number in that specific use case.
The difference from DUNS runs deep. A private vendor, Dun & Bradstreet, issued DUNS numbers. The government generates a UEI directly inside its own system, so a company no longer needs a separate third-party number. If your company wants to sell goods or services to the US federal government, you need a UEI. A DUNS number alone won’t cut it anymore.
What a GIIN is, and who it actually affects
A GIIN (Global Intermediary Identification Number) proves a foreign financial institution registered under the US FATCA (Foreign Account Tax Compliance Act) reporting regime and reports on its US account holders to the IRS. Without a valid GIIN, a 30% withholding tax automatically applies to US-source payments.
The IRS issues the code, a 19-character string. You can check its validity against the public FFI (Foreign Financial Institution) list. A GIIN mainly concerns banks, funds, and other financial intermediaries handling US clients’ assets, not ordinary trading companies. Many funds that already carry an LEI obligation under European rules also end up needing a GIIN, because the two codes serve different regulators. The LEI serves European securities regulators. The GIIN serves the US tax authority.
What an ISIN is, and how it differs from an LEI
An ISIN (International Securities Identification Number) is a 12-character alphanumeric code that identifies one specific security, say a single share class or bond issuance, not the company itself. The international standard ISO 6166 defines it, and each country’s own national numbering agency issues the codes, for example WM Datenservice in Germany, CUSIP Global Services in the US, or the London Stock Exchange in the UK. ANNA (Association of National Numbering Agencies) coordinates all of them globally.
Where LEI and ISIN diverge
This is where LEI and ISIN get confused most often, because both tend to show up in the same transaction, on the same reporting form, sometimes in the same sentence. Here’s the simplest way to keep them apart: an ISIN answers what is being traded, an LEI answers who is trading. A single company with just one LEI might have issued dozens of different securities, each with its own ISIN. The issuer, not the investor trading the security, has to obtain the ISIN.
Regulators want to track transactions at both the instrument and the counterparty level. That’s why most reporting frameworks, MiFID II included, require both an ISIN and an LEI code for a single transaction. GLEIF and ANNA strengthened that link by publishing a freely available ISIN-to-LEI mapping that lets you look up one code from the other. If your company issues securities, ISIN is already familiar territory through your issuing agent. An LEI, though, deserves its own introduction. That brings us to the core topic of this article.
What an LEI is, and why it differs from everything before it
An LEI is a 20-character alphanumeric code that identifies a legal entity worldwide in a single, consistent way, regardless of country. Unlike everything covered so far, no single country or private company created it. It’s the international standard ISO 17442, and GLEIF (Global Legal Entity Identifier Foundation) administers it. GLEIF is a not-for-profit backed by the G20, the Financial Stability Board, and the BIS (Bank for International Settlements).
What makes it different
Three things set the LEI apart. First, it answers the “who is who” question in a way that works equally well in Berlin, London, and Tokyo, with no translation needed. Second, and more important to regulators, every LEI carries ownership data showing a company’s direct and ultimate parent companies. That “who owns whom” layer explains why the LEI became a cornerstone of anti-money-laundering and financial transparency work. It also explains why none of the earlier identifiers, from a company registration number to an ISIN, can fill that role. Third, unlike a registration number that gets checked once at incorporation and then left alone, the data behind your LEI has to pass a fresh check every single year, more on that in a moment.
Where an LEI is required
Companies trading financial instruments under MiFID II (Markets in Financial Instruments Directive II) need an LEI. So do companies reporting derivatives transactions, investment funds, and any entity that falls under a growing list of regulations that already treat the LEI as the standard identifier. That list keeps expanding: LEI requirements change in 2026 across several countries, the US FDTA (Financial Data Transparency Act) takes effect in October, India made the LEI mandatory across its financial market, and the EU is building its European Business Wallet initiative around it.
The same code connects you to broader data networks too. The GLEIF-led GODIN initiative uses the LEI to link public business registers and sustainability data worldwide. Project Aperta tests how the LEI makes cross-border open finance interoperable between markets.
The annual renewal
Unlike a company registration number, a single application isn’t enough for an LEI. You have to renew the code every year, or it lapses and your transactions can stall.
That annual renewal isn’t just paperwork. Under GLEIF’s rules, your LEI issuer (an LOU, Local Operating Unit) or the RA (Registration Agent, such as us) acting on its behalf has to re-check your company’s data during every renewal. They confirm directly with you that it’s still accurate. That means your LEI issuer has validated the data behind every active LEI at least once a year, even if your company hasn’t proactively reported changes in between. Our LEI registration guide lays out how the application process works.
Why the LEI has no real competitor
The LEI has no direct competitor. The reason is simple: its strength doesn’t come from technology. It comes from the fact that over 300 regulations worldwide specifically require an LEI code, not some other identifier. Still, people often lump several identifiers in with it.
DUNS was the closest thing to a universal business identifier before the LEI, but Dun & Bradstreet still owns it privately, and it stays limited to credit assessment. GLN (Global Location Number) plays a similar role in supply chains, but it identifies locations and functions rather than legal entities as a whole. BIC (Business Identifier Code), also known as the SWIFT code, identifies banks in payment messages, but only within banking. GLEIF and SWIFT have even collaborated on a BIC-to-LEI mapping, so the two complement each other rather than compete.
The technology contenders
The most interesting activity happens on the technology side. DID (Decentralized Identifier) is a blockchain-based framework, more of a technical tool for building digital identity than a ready-made identification system with a public registry the way the LEI has. GLEIF itself explores a similar direction through the Agent Name Service concept, which would use the LEI to identify which company stands behind a given AI agent’s actions. And in February 2026, OpenCorporates launched plei, a free identifier that’s technically compatible with the LEI. OpenCorporates positioned it as a bridge to the LEI rather than a replacement: a small business can start with a plei and later grow into a full LEI once regulation requires it.
Why you’ll likely need more than one identifier
Almost certainly, yes. A company registration number proves you exist. A VAT number lets you invoice correctly across borders. An EIN opens the door to the US tax system. A DUNS number and a UEI speak to US procurement and credit systems. If your company is a fund or financial institution, a GIIN likely joins the mix. And an LEI, paired with an ISIN, speaks to regulators and exchanges worldwide.
A mid-size company trading internationally and touching financial markets will likely hold several of these at once. Each one serves a different counterparty, and none of them does another’s job.
When an LEI is actually mandatory
You need an LEI when you trade exchange-listed instruments, a requirement that only broadens once the EU moves to a T+1 settlement cycle in 2027. You also need one when you’re a counterparty in a derivatives transaction that you must report to a regulator, or when a bank or broker has asked you for one directly. Investment funds and many charities also fall under the requirement.
If none of those scenarios sound familiar but your bank sent you a letter asking for an LEI code anyway, the fastest path forward is checking exactly which regulation is behind the request. Applying is simpler than the regulatory language suggests: you submit your company’s core details to an accredited issuer and renew the code every year. Find more detail on our what is an LEI page.
Whether you need to register a new LEI or your current one is coming up for renewal, both take just a few minutes online.
Frequently asked questions
Find more common questions about the LEI on our FAQ page.
Can a DUNS number replace an LEI code?
No. DUNS remains a private-sector credit and procurement identifier. Financial market transactions and regulatory reporting specifically require an LEI instead. Neither does the other’s job.
Do I need both a VAT number and an LEI code?
Probably yes, but for different reasons. A VAT number governs how you tax cross-border trade. An LEI governs identification in financial transactions.
Is an EIN the same as an LEI?
No. An EIN is a US-specific tax identifier from the IRS. An LEI is an international ISO standard that financial markets and reporting use in every country.
Are ISIN and LEI the same thing?
No, and this is a common mix-up. An ISIN identifies a specific security, an LEI identifies the company behind it. Most regulatory reports require both.
Do I need a UEI for US federal contracts if I already have a DUNS number?
Yes. Since 2022, the US federal government directly requires the UEI for contracts and grants. A DUNS number alone no longer suffices.
How do I know if I need an LEI code?
If a bank, broker, or regulator has asked you for one directly, or if you trade financial instruments, report derivatives transactions, or run an investment fund, the answer is yes.
Is there a direct alternative to the LEI?
No. DUNS, GLN, BIC, and DID cover overlapping but narrower roles. OpenCorporates designed its new plei as a bridge to the LEI, not a competitor to it.
Does an LEI expire?
Yes, and it’s a difference worth remembering. You have to renew an LEI every year, in 1, 3, or 5-year cycles depending on the provider. Otherwise the code goes inactive and regulators stop trusting your data.