How to Get an EIN Number in Washington State: Online, Fax, or Mail

To get an EIN in Washington State, apply directly with the IRS. It’s free, it takes about ten minutes online, and you receive the nine-digit number the moment you finish the form.¹ You’ll then use that number when you file your Washington Business License Application with the Department of Revenue.

Who Needs an EIN in Washington

Federally, the IRS requires an EIN for any business with employees, excise tax obligations, or withholding on payments to non-resident aliens.² Washington goes further. The Department of Revenue expects every business type other than a sole proprietorship without employees to have one, which pulls in all LLCs, corporations, partnerships, and multi-member entities whether or not they have payroll.³

Sole proprietors without employees are the main group that can skip it. Many apply anyway, so they don’t have to put their Social Security number on every W-9 a client sends them.²

What to Have Ready Before You Start

The online application (an electronic version of Form SS-4) can’t be saved. It times out after 15 minutes of inactivity, and you lose your progress if that happens.¹ Have the following in front of you before you open the form:

The responsible party’s name and a valid SSN or ITIN. The responsible party is the individual who controls the entity and its finances.⁴
The exact legal name of the business as it’s registered or will be registered with the state.
The entity type: LLC, corporation, partnership, sole proprietorship, trust, or other.
A physical street address for the business. A P.O. box alone won’t satisfy this field.⁵
Your reason for applying, such as starting a new business or hiring employees.⁵
The number of agricultural, household, and other employees you expect in the next 12 months, including zero.⁵

The Three Ways to Apply

Online

This is the fastest route and the one most Washington applicants should use. The IRS portal generates your EIN immediately on submission. It’s open Monday through Friday 6:00 a.m. to 1:00 a.m. Eastern, Saturdays 6:00 a.m. to 9:00 p.m. Eastern, and Sundays 6:00 p.m. to midnight Eastern.¹ You must finish in a single session.

Fax

Complete a paper Form SS-4, include a return fax number, and send it to 855-641-6935 if your business is in any U.S. state or the District of Columbia.⁶ The IRS typically faxes the EIN back within four business days.⁵

Mail

Mail Form SS-4 to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999. Expect four to five weeks.⁵ This is really a fallback for people without fax access who can’t use the online tool.

Whichever method you use, the IRS mails a CP 575 notice as the official confirmation of your assigned number. Keep it. Banks and state agencies ask for it.

If the Responsible Party Has No SSN or ITIN

The online tool requires a valid taxpayer identification number for the responsible party, so if yours doesn’t have one and isn’t eligible for one, the online route is closed. Apply by fax or mail using a paper Form SS-4, writing “foreign” or “N/A” on Line 7b. International applicants without a U.S. address can also apply by phone.⁵

Using Your EIN With Washington State

Once you have the number, file a Business License Application through the Department of Revenue’s My DOR portal. That filing assigns your Unified Business Identifier (UBI) number and ties your state tax account to your EIN.³ Washington’s registration framework under WAC 458-20-101 uses the UBI to coordinate records across the Department of Revenue, the Department of Labor and Industries, and other participating agencies through a single application.⁷

The Business License Application has a $50 non-refundable processing fee each time you submit it, and endorsement fees can add to that depending on your activity and location.⁸ That’s separate from any Secretary of State fees for forming an LLC or corporation.

Banks will also want the EIN, along with your formation documents and business license, before they’ll open a commercial account.⁹

When You Need a New EIN Later

Changing your business name or address does not require a new EIN. Changes to ownership or structure usually do, and the triggers depend on your entity type.¹⁰

Sole proprietors need a new EIN if they incorporate, form a partnership, or declare bankruptcy.
Corporations need a new EIN after receiving a new charter from the secretary of state, becoming a subsidiary of another corporation, converting to a partnership or sole proprietorship, or merging into a newly created corporation.
Partnerships need a new EIN after incorporating, after dissolving and starting a new partnership, or when one partner takes over the business as a sole proprietor.
LLCs need a new EIN after terminating and forming a new corporation or partnership, or when a single-member LLC must begin filing employment or excise taxes.

Converting a Washington sole proprietorship into an LLC is a common trigger that catches owners off guard. You can’t carry the old number forward. Apply for the new EIN before you start filing taxes under the new structure.¹⁰

Keeping Your IRS Account Current

If the responsible party on file changes, you have 60 days to report it to the IRS using Form 8822-B.¹¹ This matters when a founding member leaves, a new owner takes over, or a managing partner changes.

For a name change, sole proprietors write to the IRS address where they file their return. Corporations check the name-change box on Form 1120 or 1120-S, and partnerships check the equivalent box on Form 1065. If you’ve already filed for the year, send a signed letter instead.¹²

Don’t Pay for an EIN

The IRS never charges a fee for an EIN. Sites that ask for $50 to $300 to “file” one for you are reselling a free product, and some are outright scams dressed up with government-looking branding.¹ The real application lives at irs.gov. Search “apply for EIN” there directly rather than clicking through an unfamiliar link.

Finding an EIN You’ve Lost

Check your CP 575 notice, a prior tax return, your bank records, or any state or local agency where you’ve used the number.² If none of those turn it up, call the IRS Business and Specialty Tax Line at 800-829-4933, Monday through Friday 7:00 a.m. to 7:00 p.m. local time. After verifying your identity, they can read the number back to you or send a 147C confirmation letter.

1
Internal Revenue Service. Get an Employer Identification Number
2
Internal Revenue Service. Employer Identification Number
3
Washington Department of Revenue. Business Licensing and Renewals FAQs
4
Federal Register. Updating of Employer Identification Numbers
5
Internal Revenue Service. Instructions for Form SS-4 (12/2025)
6
Internal Revenue Service. Where to File Your Taxes for Form SS-4
7
Washington State Legislature. WAC 458-20-101 Tax Registration and Tax Reporting
8
Washington Department of Revenue. State Endorsement Fee Sheet
9
U.S. Small Business Administration. Open a Business Bank Account
10
Internal Revenue Service. When to Get a New EIN
11
Internal Revenue Service. Form 8822-B, Change of Address or Responsible Party – Business
12
Internal Revenue Service. Business Name Change