A Tax ID Number Is Nine Digits, Usually Formatted With a Hyphen

A Tax ID number (also called an Employer Identification Number or EIN) is a nine-digit code the IRS assigns to businesses, nonprofits, trusts, and some individuals. It always appears in the format XX-XXXXXXX — two digits, a hyphen, then seven digits. For example: 12-3456789. There is no variation in this format; if you see a number that does not follow this pattern, it is not a Tax ID.

The IRS issues Tax IDs to identify entities for tax purposes, similar to how a Social Security number identifies a person. If you run a business, manage a nonprofit, or hold certain types of accounts, you will have a Tax ID rather than (or in addition to) a Social Security number for tax reporting.

The first two digits do not encode information about your location or business type — they are straightforward part of the sequential numbering system the IRS uses. You cannot decode a Tax ID to learn where it was issued or what kind of business holds it.

Key Takeaways

  • A Tax ID number is always nine digits in the format XX-XXXXXXX, with no exceptions or variations.
  • The IRS assigns Tax IDs to businesses, nonprofits, trusts, and certain individuals; they serve the same identification purpose as a Social Security number does for people.
  • You cannot determine a business type, location, or issue date by looking at a Tax ID number alone.
  • Your Tax ID appears on business tax returns, W-2 forms sent to employees, and official IRS correspondence.
  • If someone asks for a nine-digit number in a different format, they are not asking for a Tax ID.

Where You Will See a Tax ID on Official Documents

When you receive official paperwork from the IRS or from a business you work with, the Tax ID appears in a consistent location. On a Form 1098 (mortgage interest statement) or Form 1099 (income from freelance work, interest, or dividends), the business's Tax ID is printed in the upper right corner. On a W-2 form (wage statement from an employer), it appears in box b, near the top left.

If you own a business and receive IRS letters, your Tax ID is printed on the envelope and at the top of the letter itself. Banks and financial institutions also print your Tax ID on statements if the account is held under a business name or trust.

You can also find your own Tax ID on the Form SS-4 confirmation letter the IRS sends when you first request one, or on your Form 941 (quarterly payroll tax return) if you have employees.

How a Tax ID Differs From a Social Security Number

A Social Security number has nine digits but is formatted as XXX-XX-XXXX (three digits, hyphen, two digits, hyphen, four digits). A Tax ID is formatted as XX-XXXXXXX (two digits, hyphen, seven digits). This difference in format makes them straightforward to tell apart at a glance.

The IRS assigns Social Security numbers to individuals for personal tax reporting. Tax IDs are assigned to businesses, nonprofits, partnerships, corporations, and trusts. A sole proprietor (someone running a business alone) may use their Social Security number for tax purposes instead of getting a Tax ID, though many choose to get one anyway for privacy and accounting reasons.

If you see a nine-digit number on a business document and it is formatted XX-XXXXXXX, it is a Tax ID. If it is formatted XXX-XX-XXXX, it is a Social Security number, and the document is identifying an individual rather than a business entity.

What the Numbers Mean (and What They Do Not)

The IRS does not publish the meaning of individual digits within a Tax ID. Unlike some government ID systems, the first two digits do not indicate the state where the business is located, the year it was issued, or the type of business. The nine digits are straightforward a unique identifier assigned sequentially by the IRS.

You cannot look up a business by its Tax ID number using a public search tool. The IRS does not maintain a public directory matching Tax IDs to business names or addresses. If you need to verify that a Tax ID belongs to a specific business, you would need to contact the business directly or check your own records.

Some states maintain their own business registries and may cross-reference Tax IDs with business names, but these are state-level databases, not federal ones, and access varies by state.

Where to Find Your Tax ID If You Have Lost It

If you own a business and cannot locate your Tax ID, check any of these sources first: the IRS letter you received when you originally requested the number, your business tax returns from previous years, bank statements or loan documents held under the business name, or correspondence from the IRS.

If you still cannot find it, you can contact the IRS directly. Call the Business and Specialty Tax Line at 1-800-829-4933 (Monday through Friday, 7 a.m. to 7 p.m. your local time). Have your business name, address, and date of birth ready. The IRS can confirm your Tax ID over the phone.

You can also request a new Tax ID using Form SS-4 if your original number is truly lost and you cannot retrieve it through the IRS. The IRS will issue a new number, though this is uncommon — most businesses keep the same Tax ID throughout their existence.

Tax IDs on Business Websites and Public Records

Some businesses display their Tax ID on their website or in business directories, but this is optional and not required by law. A business that publishes its Tax ID is not hiding anything — it is straightforward making it straightforward for customers, vendors, or employees to reference it.

Certain business filings, such as nonprofit incorporation documents or LLC formation papers, may include the Tax ID if the business has already obtained one at the time of filing. These documents are often public record at the state level, so a Tax ID may appear in a state business database.

However, the IRS itself does not publish a searchable public list of Tax IDs and their corresponding businesses. If you need to confirm a Tax ID belongs to a specific company, ask the company directly or check your own records of correspondence with them.

Frequently Asked Questions

Can I use my Social Security number instead of getting a Tax ID for my business?

Yes, if you are a sole proprietor with no employees, you can use your Social Security number on your tax return instead of getting a Tax ID. However, many sole proprietors get a Tax ID anyway for privacy reasons and to keep business and personal finances separate on tax documents. Getting a Tax ID is free and takes about 15 minutes online through the IRS website.

What if someone asks me for a Tax ID in a different format?

If someone asks for a nine-digit number but specifies a format other than XX-XXXXXXX, they are not asking for a Tax ID. They may be asking for a Social Security number, state tax ID, or some other identifier. Clarify what number they actually need before providing any information.

Is a Tax ID the same as a business license number?

No. A Tax ID is issued by the federal IRS for tax reporting purposes. A business license number is issued by your city or county and is required to legally operate a business in that location. They are separate numbers, and you may need both depending on your business type and location.

Can I look up a company's Tax ID online?

The IRS does not maintain a public searchable database of Tax IDs. However, some state business registries and nonprofit databases may list Tax IDs alongside business names. Your best option is to contact the business directly or check documents you have received from them, such as invoices or tax forms.

What happens if I give my Tax ID to the wrong person?

A Tax ID alone does not grant access to your business accounts or allow someone to file taxes in your name. However, it is still wise to treat it like other business information — do not share it with people who do not have a legitimate business reason to know it. If you are concerned someone has misused your Tax ID, contact the IRS at 1-800-829-4933.