DUNS Number vs EIN vs Tax ID: What's the Difference?

Why People Mix These Up

All three show up on forms that ask you to "identify your business," which is exactly why they get confused. They're also all short strings of digits, and more than one of them is nine digits long, so it's easy to assume they're interchangeable versions of the same thing. They aren't. Each number was built by a different organization, for a different reason, and none of them can substitute for another when a form specifically asks for it.

If you've landed here because a platform like Apple Developer or Google Play asked for a DUNS number and you're wondering whether your EIN will do the job, the short answer is no — but read on, because understanding why will save you time on every form you fill out from here on.

What Is a DUNS Number?

A DUNS (Data Universal Numbering System) number is a unique nine-digit identifier issued by Dun & Bradstreet, a private business-data and credit-reporting company — not a government agency. It was created decades ago as a way to track individual business locations across D&B's global database, and it's since become the de facto standard that companies, platforms, and agencies use when they need to verify that a business is real and locate its credit history.

A DUNS number doesn't expire and doesn't change even if your business changes its legal structure or ownership, because it's tied to the physical location and identity D&B has on file, not to your tax status. You can register for one for free directly through D&B, a process we walk through in our Getting Started guide.

What Is an EIN?

An EIN (Employer Identification Number) is a nine-digit number issued by the Internal Revenue Service, the U.S. federal tax authority. Its entire purpose is tax administration: it's how the IRS tracks your business for income tax, payroll tax, and other federal filing obligations, and it's typically what banks and lenders ask for when you open a business account or apply for credit.

Unlike a DUNS number, an EIN can change — if your business restructures (say, from a sole proprietorship to an LLC) or changes ownership in certain ways, the IRS may require you to apply for a new one. Getting an EIN is also free and can usually be done online in a single sitting directly through the IRS.

What Is a "Tax ID"?

"Tax ID" isn't a single specific number — it's an umbrella term for whatever identifier the IRS uses to track a taxpayer, business or individual. Depending on your situation, your Tax ID could be:

• An EIN — for most registered businesses, partnerships, and corporations
• A Social Security Number (SSN) — commonly used by sole proprietors who haven't applied for an EIN
• An ITIN (Individual Taxpayer Identification Number) — issued to individuals who need to file U.S. taxes but aren't eligible for an SSN, often non-resident business owners

So when a form asks for your "Tax ID," it's really asking for whichever of these applies to you — it's a category, not a fourth separate number sitting alongside DUNS and EIN.

Side-by-Side Comparison

Do You Need All Three?

Most established businesses end up holding more than one of these, simply because each one unlocks something different:

A sole proprietor running a small local shop with no employees might never need a DUNS number. A software developer trying to list an app on the Apple App Store as a company, on the other hand, will need one regardless of how small the business is, because Apple requires it as part of its business verification process.

An Important Wrinkle: DUNS and the Federal Government

If you've seen older guidance saying the U.S. federal government requires a DUNS number for grants and contracts, that's now outdated. As of April 2022, the federal government's contractor and grant-tracking system, SAM.gov, replaced DUNS numbers with its own identifier called the Unique Entity Identifier (UEI). If you're applying for a federal grant or contract today, SAM.gov will assign you a UEI directly — you no longer need to get a DUNS number first for that specific purpose.

That said, this change only affects federal government registration. Your DUNS number remains fully active and separately relevant for D&B's own credit-reporting system and for private companies — including Apple, Google, and Amazon — that still use it as their standard for business verification. In other words, getting a UEI doesn't replace the need for a DUNS number if a private platform specifically asks for one.

How to Tell Which One a Form Is Actually Asking For

When you're stuck staring at a form field, a quick way to figure out what's actually being requested:

1. If the form mentions "D&B," "Dun & Bradstreet," or is coming from a private platform like Apple, Google, or Amazon — it wants your DUNS number.
2. If the form is about payroll, opening a bank account, or filing taxes — it wants your EIN (or SSN/ITIN if you're a sole proprietor without one).
3. If the form is a U.S. federal government grant or contract portal — it wants your UEI from SAM.gov, not a DUNS number.

A Real-World Example

Here's how these three numbers actually play out for a typical small business. Say you register an LLC to sell software. Your first step is usually applying for an EIN through the IRS, since you'll need it to open a business bank account and, eventually, to file your first tax return — this EIN also becomes your business's Tax ID from that point forward.

Months later, you decide to publish an app on the Apple App Store as a registered company rather than an individual developer. Apple's enrollment process asks for a DUNS number to verify your business is legitimate. Your EIN doesn't help here — Apple's system checks against D&B's database, not the IRS's — so you separately register for a free DUNS number through Dun & Bradstreet. Nothing about your EIN changes, and nothing about your DUNS number depends on it; the two simply sit in parallel, each doing its own job.

If later on your business grows enough to bid on a federal contract, you'd register in SAM.gov, which issues you a UEI directly — again, independent of both the EIN you already have and the DUNS number you registered for Apple. By that point you could easily be holding all three types of identifiers at once, each unlocked by a different milestone in the business's growth rather than by one number leading to another.

Why This Confusion Costs Businesses Time

The most common support question we see isn't "how do I get a DUNS number" — it's "why was my application rejected." Almost always, the cause traces back to someone submitting the wrong identifier, or assuming that having one number means they automatically qualify for, or already have, another. A rejected Apple Developer application because an EIN was entered instead of a DUNS number, for example, can add days or weeks to a launch timeline that a five-minute lookup would have avoided.

Keeping a simple record of which number belongs to which system — ideally saved somewhere your whole team can access — is a small habit that prevents a surprising amount of friction later, especially once a business starts dealing with multiple platforms, vendors, and government portals that each expect a specific type of ID.

The Bottom Line

Think of it this way: your EIN is your business's relationship with the IRS, your DUNS number is your business's relationship with Dun & Bradstreet and the private companies that rely on D&B data, and your Tax ID is simply whichever federal number — EIN, SSN, or ITIN — applies to you personally or to your business. None of them replace each other, and getting one doesn't automatically get you the others. If you're not sure which one a specific form or platform is asking for, that's usually the fastest thing to clarify before you start filling anything in.