What Is a FEIN Number in California and Who Needs One?

A FEIN in California is the same federal employer identification number the IRS issues everywhere else: a free, nine-digit number (formatted XX-XXXXXXX) that identifies your business, nonprofit, estate, or trust for federal tax purposes. It works like a Social Security number for the entity, it stays with that entity permanently once assigned, and you get it directly from the IRS at no cost.1Internal Revenue Service. Get an Employer Identification Number

Third-party sites that charge $79 or more to “file” the application are not affiliated with the IRS. The application itself takes about ten minutes.

Who Needs a FEIN in California

The IRS requires an EIN if your business is a corporation (C or S), a partnership of any kind, a multi-member LLC, or a single-member LLC that has elected corporate tax treatment on Form 8832. Any business that hires an employee needs one the moment the first worker comes on. Trusts, estates, and nonprofits each need their own.2Internal Revenue Service. Employer Identification Number

Sole Proprietors

If you run a one-person operation with no employees, you can legally use your Social Security number on tax returns instead. Getting an EIN anyway keeps your SSN off every W-9 you hand to a client and separates your business identity from your personal one at banks and vendors.

Household Employers

This one catches California families. If you pay a nanny, housekeeper, or other household worker $3,000 or more in cash wages during 2026, you must withhold Social Security and Medicare taxes, and reporting those taxes and issuing a W-2 requires an EIN.3Internal Revenue Service. 2026 Publication 926 You also need one below that threshold if you and the worker agree to voluntary federal income tax withholding.4Internal Revenue Service. Topic No. 756, Employment Taxes for Household Employees

How to Apply

The IRS collects the same information whether you apply online, by fax, or by mail: it all comes through Form SS-4. Have this ready before you start, because the online session times out after 15 minutes of inactivity and cannot be saved:5Internal Revenue Service. Form SS-4 (Rev. December 2025)

  • Legal name and any trade name or DBA.
  • Entity type (corporation, partnership, LLC, sole proprietorship, trust, estate, or nonprofit).
  • Physical and mailing addresses, including county and state.
  • The responsible party’s name and SSN or ITIN. For a corporation this is a principal officer; for a partnership, a general partner; for a trust, the grantor.
  • Reason for applying (new business, hiring employees, banking, and so on).
  • Business start date and the month your fiscal year ends.
  • Highest number of employees you expect in the next 12 months.

The responsible party must be a real individual, not another entity. The IRS specifically prohibits listing a “nominee” with only formation-stage authority, because doing so can expose personal information to people who should not have access to the account.6Internal Revenue Service. Responsible Parties and Nominees

Online

The IRS online EIN assistant is the fastest route. You answer the questions, submit, and the number appears on screen immediately. Print or save the confirmation page; that is your official proof until the formal CP 575 notice arrives in the mail several weeks later. The tool is open Monday through Friday from 6:00 a.m. to 1:00 a.m. Eastern, Saturday 6:00 a.m. to 9:00 p.m. Eastern, and Sunday 6:00 p.m. to midnight Eastern.1Internal Revenue Service. Get an Employer Identification Number It requires that your principal place of business be in the United States and that the responsible party have a valid SSN or ITIN.

Fax and Mail

If you cannot use the online system, submit a paper Form SS-4. Fax typically produces an EIN within four business days; mail takes four to five weeks. Plan ahead if you need the number to open a bank account or register with the EDD on a deadline.7Internal Revenue Service. Instructions for Form SS-4 (12/2025)

International Applicants

If your business has no legal residence or principal office in the United States, the online tool is not available. Call 267-941-1099 (not toll-free) Monday through Friday, 6:00 a.m. to 11:00 p.m. Eastern. The caller must be authorized to receive the EIN and answer the Form SS-4 questions, or you can designate someone to receive it on your behalf through the Third Party Designee section of the form.7Internal Revenue Service. Instructions for Form SS-4 (12/2025)

Your FEIN Is Not Your California Entity Number

California businesses typically carry two identification numbers, and confusing them wastes time at the state agencies. Your FEIN comes from the IRS. Your California entity number comes from the Secretary of State when you register your business. Different agencies, different numbers.

The distinction matters most at the Franchise Tax Board. The FTB no longer accepts a FEIN to register for MyFTB, add a business to your account, or request a Tax Information Authorization. You have to use the entity number issued by the California Secretary of State or, if you are not registered with the SOS, the ID number the FTB itself assigned you. Your FEIN still appears on your federal returns and the FTB cross-references it, but it is not the key that unlocks your California state tax account.8Franchise Tax Board. Business Entity ID Number Help

Registering for California Payroll Taxes

If you pay more than $100 in wages during any calendar quarter, you must register with the Employment Development Department within 15 days to begin reporting state payroll taxes: Unemployment Insurance and Employment Training Tax paid by the employer, plus State Disability Insurance and Personal Income Tax withheld from employee wages.9Employment Development Department. Employers: Payroll Tax Account Registration

Registration goes through the EDD’s e-Services for Business portal, and your FEIN is required as part of the application. The EDD uses it to link your new state payroll account to your federal tax identity.10Employment Development Department. Payroll Taxes

When You Need a New EIN

Changing your business structure usually means getting a new EIN, because the IRS treats many structural changes as creating a new entity even when the people and operations do not change. The common triggers:11Internal Revenue Service. When to Get a New EIN

  • A sole proprietor incorporates or forms a partnership. The new entity needs its own number.
  • A corporation merges into a new corporation and the survivor receives a new charter.
  • A corporation converts to a sole proprietorship or partnership.
  • A partnership ends and a new one begins, even with the same partners.
  • An LLC terminates and re-forms as a corporation or partnership.
  • A sole proprietor declares bankruptcy. The bankruptcy estate is a separate taxable entity.

You do not need a new EIN just because you changed your business name, moved, or added a DBA. Those are reported on your next return or through a separate notification.

Closing a Business and Deactivating the Account

The IRS cannot cancel an EIN. Once assigned, the number stays tied to your entity forever. What the IRS can do is deactivate your business tax account so you no longer have filing obligations. Before you ask for deactivation, file all outstanding returns and pay what you owe. Corporations also file Form 966 when they adopt a plan to dissolve.12Internal Revenue Service. Closing a Business

To deactivate, mail the IRS a letter with the entity’s EIN, legal name, address, the EIN assignment notice if you still have it, and the reason for deactivating. Send it to the IRS at Kansas City, MO 64108 or Ogden, UT 84201. Exempt organizations use a separate address and can also fax the request to 855-214-7520.13Internal Revenue Service. If You No Longer Need Your EIN

Check the “final return” box on your last income tax filing, and for partnerships mark the “final K-1” box on each partner’s Schedule K-1. Skip this and the IRS keeps expecting returns, which eventually produces notices and penalties.