State Tax ID vs Federal EIN: What Is the Difference?

What a federal EIN is

The Employer Identification Number is a nine-digit number in the format 12-3456789 that the IRS assigns to a business entity. Despite the name, you do not need employees to have one. It identifies the business on federal tax returns, on the account application at any bank, on credit applications, on W-9s you give to customers and on the W-2s and 1099s you issue. It never changes and never expires, and there is only ever one per entity. The uses guide lists everything it unlocks.

What a state tax ID is

There is no single “state tax ID.” The phrase covers several account numbers a state assigns when you register for a particular tax, and which ones you get depends on what the business does. The common ones:

• Sales tax permit or seller’s permit number. Issued by the state revenue department when you register to collect sales tax. Required before your first taxable sale in most states.
• State withholding account number. Issued when you register to withhold state income tax from employee wages. This is the number that goes in box 15 of a W-2, labelled “Employer’s state ID number.”
• Unemployment insurance (SUI) account number. Issued by the state labor or workforce agency when you become an employer. Some states combine it with withholding; many do not.
• State entity or filing number. Not a tax ID at all, but often mistaken for one. It is the number the Secretary of State stamped on your formation filing. It identifies the company in state records and cannot be used anywhere an EIN or tax account number is asked for.

A few states issue one master taxpayer number and hang the individual tax accounts off it. Texas does this with the Comptroller’s eleven-digit taxpayer number; Florida issues a business partner number when you register on Form DR-1. Most states issue a separate number per tax.

Which number goes where

Which one you get first

The federal EIN. Almost every state registration form has a line for it, and several state portals refuse to open an account without one. The order for a new business is: state approves the entity, IRS issues the EIN, then the state revenue agency issues the tax accounts you actually need. Sole proprietors with no employees and no taxable sales may never need a state number at all; the state pages say what each state requires once you hold the EIN.

Do I need both?

You need the EIN if you have employees, more than one owner, a corporate election, or a bank account in the business’s name, which covers nearly every LLC and corporation. You need a state number only for the specific taxes the state makes you register for: sales tax if you sell taxable goods or services in that state, withholding and unemployment if you pay wages there. A consultant with no employees in a state with no sales tax on services may hold an EIN and no state number for years.

Quick answers

Is the employer’s state ID number the same as the EIN?

No. Box b of the W-2 is the federal EIN; box 15 is the state withholding account number the state assigned when you registered as an employer. If you have never registered for withholding in that state, box 15 is the thing you are missing, not the EIN.

Can I use my EIN as my state tax ID?

A few state portals let you log in with the EIN, and some states print it on the account, but the state account number itself is a separate number. Putting the EIN on a sales tax return in a state that expects its own permit number is a common cause of misapplied payments.

Is my state LLC number a tax ID?

No. It is the registry’s file number for your formation documents. It goes on the annual report and nowhere else.

How do I find a state tax ID I already have?

It is printed on the registration confirmation the state sent, on every return filed under it, and in your payroll provider’s tax setup screen. State revenue agencies will also read it to an authorized owner over the phone. For a lost federal EIN, the route is different; see the 147C letter guide.