Form SS-4: EIN Application, Online Hours, Fax and Mail Addresses, Line by Line
Form SS-4 is the IRS application for an employer identification number (EIN). When we checked on November 2, 2026, the IRS listed Form SS-4 (Rev. December 2025), said an EIN can be had free online by applicants in the United States or U.S. territories, and said EIN issuances are limited to one per responsible party, per day.
Maintained by Archie Chang · Reviewed November 2, 2026 · Methodology & sources
What Form SS-4 does
The IRS About Form SS-4 page and the Instructions for Form SS-4 (Rev. December 2025) describe the form like this:
“Use Form SS-4 to apply for an employer identification number (EIN). An EIN is a 9-digit number (for example, 12-3456789) assigned to employers, sole proprietors, corporations, partnerships, estates, trusts, certain individuals, and other entities for tax filing and reporting purposes.”
“Use Form SS-4 to apply for an EIN. An EIN is a 9-digit number (for example, 12-3456789) assigned to sole proprietors, corporations, partnerships, estates, trusts, and other entities for tax filing and reporting purposes. The information you provide on this form will establish your business tax account.”
“An EIN is for use in connection with your business activities only. Don’t use your EIN in place of your social security number (SSN) or individual taxpayer identification number (ITIN).”
“Note: Keep the Form SS-4 information current. Use Form 8822-B to report changes to your responsible party, address or location. Changes in responsible parties must be reported to the IRS within 60 days.”
The IRS Employer identification number page has two lists of who needs an EIN, and a note after them:
“You need an EIN if you:
Have employees
Will need to pay employment, excise or alcohol, tobacco, and firearms taxes
Withhold taxes on income, other than wages, paid to a non-resident alien”
“You also need an EIN to operate any of these entities:
Partnership
Limited liability company (LLC)
Corporation
Tax-exempt organization
Estate
Trust PDF (except certain grantor-owned revocable trusts)
Retirement plan or individual retirement account (IRA)
Real estate mortgage investment conduit
Farmers' cooperative”
The “PDF” in the Trust line is the IRS page’s link label for a PDF.
“If you don’t need an EIN for federal tax purposes, you can still request one for banking or state tax purposes. EINs are not intended for other activities, such as state tax lien auctions, sales or lotteries.”
Ways to apply: online, fax, mail and telephone
“The IRS recommends that you apply for your EIN electronically, if possible.”
“Use only one method for each entity so you don’t receive more than one EIN for an entity.”
| Way to apply | Who the IRS says can use it | Where | Time or hours |
|---|---|---|---|
| Online | If you have a legal residence, principal place of business, or principal office or agency in the United States or U.S. territories, you can receive an EIN online and use it immediately to file a return or make a payment. | IRS.gov/EIN | This tool is available during the following times (Eastern Time): Mon–Fri: 6:00 a.m. – 1:00 a.m. (next day) Sat: 6:00 a.m. – 9:00 p.m. Sun: 6:00 p.m. – 12:00 a.m. |
| Telephone (international applicants only) | If you have NO legal residence, principal place of business, or principal office or agency in the United States or U.S. territories, you may call | 267-941-1099 (not a toll-free number) | 6:00 a.m. to 11:00 p.m. (Eastern time), Monday through Friday |
| Fax, 50 states and D.C. | If you have a legal residence, principal place of business, or principal office or agency in one of the 50 states or the District of Columbia, fax the form to | 855-641-6935 | Under the Fax-TIN program, you can receive your EIN by fax generally within 4 business days. Fax-TIN is available 24 hours a day, 7 days a week. |
| Fax, elsewhere | If you don't have a legal residence, principal place of business, or principal office or agency in any state or in the District of Columbia (this could occur if you are in a U.S. territory or an international location), fax your form to | 855-215-1627 (if within the United States) or 304-707-9471 (if outside the United States) | Under the Fax-TIN program, you can receive your EIN by fax generally within 4 business days. Fax-TIN is available 24 hours a day, 7 days a week. |
| Mail, 50 states and D.C. | If you have a legal residence, principal place of business, or principal office or agency in one of the 50 states or the District of Columbia, mail the form to: | Internal Revenue Service Attn: EIN Operation Cincinnati, OH 45999 | Complete Form SS-4 at least 4 to 5 weeks before you will need an EIN. You will receive your EIN in the mail in approximately 4 weeks. |
| Mail, elsewhere | If you don't have a legal residence, principal place of business, or principal office or agency in any state or in the District of Columbia (this could occur if you are in a U.S. territory or an international location), mail your form to: | Internal Revenue Service Attn: EIN International Operation Cincinnati, OH 45999 | Complete Form SS-4 at least 4 to 5 weeks before you will need an EIN. You will receive your EIN in the mail in approximately 4 weeks. |
The fax rows share one timing cell and the mail rows share one, because the instructions give those sentences for the method as a whole.
The Instructions for Form SS-4 (Rev. December 2025) do not give the hours of the online application.
“Apply by fax. Under the Fax-TIN program, you can receive your EIN by fax generally within 4 business days.”
“Fax-TIN numbers can only be used to apply for an EIN. The numbers may change without notice. Fax-TIN is available 24 hours a day, 7 days a week.”
“Apply by mail. Complete Form SS-4 at least 4 to 5 weeks before you will need an EIN. Sign and date the application and mail it to the appropriate address.”
Both the instructions and the IRS Employer identification number page give “approximately 4 weeks” for receiving an EIN by mail, and the instructions also give the “at least 4 to 5 weeks” lead time quoted here. Both statements are IRS wording.
“Call 800-829-4933 to verify a number or to ask about the status of an application by mail.”
“The IRS no longer issues EINs by telephone for domestic taxpayers. Only international applicants can receive an EIN by telephone.”
The online application
“Apply for an EIN online. If you have a legal residence, principal place of business, or principal office or agency in the United States or U.S. territories, you can receive an EIN online and use it immediately to file a return or make a payment.”
“The principal officer, general partner, grantor, owner, trustor, etc., must have a valid taxpayer identification number (SSN, EIN, or ITIN) in order to use the online application.”
“Complete the application in one session.
You can't save it for later.
It expires after 15 minutes of inactivity, and you’ll need to start over.”
“Use this if all of these are correct:
You are a domestic organization, formed or created in the United States or U.S. territories.
Your principal place of business is in the U.S. or U.S. territories.
You're the responsible party in control of the entity or its authorized representative.
You have the responsible party’s Social Security number (SSN) or individual taxpayer ID number (ITIN).”
“You can't use this if either:
Your principal place of business is outside the U.S. If so, apply by phone, fax or mail.
You are applying with an EIN (unless you are government entity).”
The two IRS texts differ on the number: the instructions name “SSN, EIN, or ITIN”, while the Get an employer identification number page lists an SSN or ITIN for the responsible party and, among the cases where the tool cannot be used, applying with an EIN (unless the applicant is a government entity). Both were on irs.gov when we checked on November 2, 2026.
“If you have NO legal residence, principal place of business, or principal office or agency in the United States or U.S. territories, you can’t use the online application to obtain an EIN. Please use one of the other methods to apply.”
“Beware of websites that charge for an EIN. You never have to pay a fee for an EIN.”
“You can use your EIN immediately for most business needs. For example, when you:
Open a bank account
Apply for business licenses
File a tax return by mail
Wait up to 2 weeks to:
Pass an IRS Taxpayer ID Number (TIN) Matching Program
E-file a tax return
[…]”
One EIN per responsible party per day
Three IRS documents state the daily limit, each in its own words:
| Document | IRS text |
|---|---|
| Instructions for Form SS-4 (Rev. December 2025) | To ensure fair and equitable treatment for all taxpayers, EIN issuances are limited to one per responsible party, per day. For trusts, the limitation is applied to the grantor, owner, or trustor. For estates, the limitation is applied to the decedent (decedent estate) or the debtor (bankruptcy estate). This limitation is applicable to all requests for EINs whether online, telephone, fax, or mail. |
| IRS Get an employer identification number page | You can apply for only 1 EIN per responsible party per day. |
| IRS Employer identification number page | You can apply only for 1 EIN per day, whether online or by phone, mail or fax. |
“File only one Form SS-4. Generally, a sole proprietor should file only one Form SS-4 and needs only one EIN, regardless of the number of businesses operated as a sole proprietorship or trade names under which a business operates. However, if a sole proprietorship incorporates or enters into a partnership, a new EIN is required. Also, each corporation in an affiliated group must have its own EIN.”
“EIN applied for, but not received. If you don’t have an EIN by the time a return is due, write “Applied For” and the date you applied in the space shown for the number. Don’t show your SSN as an EIN on returns.”
Responsible party
“On the EIN application, you must name the person in charge of the entity and its assets, called the responsible party.”
“Responsible party defined. The “responsible party” is the person who ultimately owns or controls the entity or who exercises ultimate effective control over the entity. The person identified as the responsible party should have a level of control over, or entitlement to, the funds or assets in the entity that, as a practical matter, enables the person, directly or indirectly, to control, manage, or direct the entity and the disposition of its funds and assets.”
“Unless the applicant is a government entity, the responsible party must be an individual (that is, a natural person), not an entity. If you are applying for an EIN for a government entity, you may enter an EIN for the responsible party on line 7b. Otherwise, you must enter an SSN or ITIN on line 7b.”
The instructions give five situations for who the responsible party is:
“For entities with shares or interests traded on a public exchange, or that are registered with the Securities and Exchange Commission, the responsible party:
(a) If the entity is a corporation, is the principal officer; and
(b) If the entity is a partnership, is a general partner.”
“For tax-exempt organizations, the responsible party is generally the same as the “principal officer” as defined in the Form 990 instructions.
For government entities, the responsible party is generally the agency or agency representative in a position to legally bind the particular government entity.
For trusts, the responsible party is a grantor, owner, or trustor.
For decedent estates, the responsible party is the executor, administrator, personal representative, or other fiduciary.”
“Nominees are not authorized to apply for an EIN.”
“File Form 8822-B to report any subsequent changes to responsible party information. Any entity with an EIN is required to report a change in its “responsible party” on lines 8 and 9 within 60 days of the change.”
The 18 lines of Form SS-4
The labels below are copied from page 1 of Form SS-4 (Rev. December 2025). The instructions explain each line in more detail; the checkbox options under lines 9a, 10 and 16 are not copied here.
| Line | Label as printed |
|---|---|
| 1 | Legal name of entity (or individual) for whom the EIN is being requested |
| 2 | Trade name of business (if different from name on line 1) |
| 3 | Executor, administrator, trustee, “care of” name |
| 4a | Mailing address (room, apt., suite no. and street, or P.O. box) |
| 4b | City, state, and ZIP code (if foreign, see instructions) |
| 5a | Street address (if different) (Don’t enter a P.O. box.) |
| 5b | City, state, and ZIP code (if foreign, see instructions) |
| 6 | County and state where principal business is located |
| 7a | Name of responsible party |
| 7b | SSN, ITIN, or EIN |
| 8a | Is this application for a limited liability company (LLC) (or a foreign equivalent)? |
| 8b | If 8a is “Yes,” enter the number of LLC members |
| 8c | If 8a is “Yes,” was the LLC organized in the United States? |
| 9a | Type of entity (check only one box). Caution: If 8a is “Yes,” see the instructions for the correct box to check. |
| 9b | If a corporation, name the state or foreign country (if applicable) where incorporated |
| 10 | Reason for applying (check only one box) |
| 11 | Date business started or acquired (month, day, year). See instructions. |
| 12 | Closing month of accounting year |
| 13 | Highest number of employees expected in the next 12 months (enter -0- if none). If no employees expected, skip line 14. |
| 14 | If you expect your employment tax liability to be $1,000 or less in a full calendar year and want to file Form 944 annually instead of Forms 941 quarterly, check here. (Your employment tax liability will generally be $1,000 or less if you expect to pay $5,000 or less, $6,536 or less if you're in a U.S. territory, in total wages.) If you don't check this box, you must file Form 941 for every quarter |
| 15 | First date wages or annuities were paid (month, day, year). Note: If applicant is a withholding agent, enter date income will first be paid to nonresident alien (month, day, year) |
| 16 | Check one box that best describes the principal activity of your business. |
| 17 | Indicate principal line of merchandise sold, specific construction work done, products produced, or services provided. |
| 18 | Has the applicant entity shown on line 1 ever applied for and received an EIN? |
Frequently asked questions
What is Form SS-4?
The IRS About Form SS-4 page says to use Form SS-4 to apply for an employer identification number (EIN), a 9-digit number assigned to employers, sole proprietors, corporations, partnerships, estates, trusts, certain individuals, and other entities for tax filing and reporting purposes. When we checked on November 2, 2026, the IRS listed Form SS-4 (Rev. December 2025).
When is the online EIN application available?
When we checked on November 2, 2026, the IRS Get an employer identification number page said the tool is available during the following times (Eastern Time): Mon–Fri 6:00 a.m. – 1:00 a.m. (next day), Sat 6:00 a.m. – 9:00 p.m., and Sun 6:00 p.m. – 12:00 a.m. It said the application must be completed in one session and expires after 15 minutes of inactivity.
What are the fax numbers and mailing addresses for Form SS-4?
When we checked on November 2, 2026, the Instructions for Form SS-4 (Rev. December 2025) gave fax 855-641-6935 and mail to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999 for applicants with a legal residence, principal place of business, or principal office or agency in one of the 50 states or the District of Columbia. For others they give fax 855-215-1627 (within the United States) or 304-707-9471 (outside the United States), and mail to Internal Revenue Service, Attn: EIN International Operation, Cincinnati, OH 45999. They add: “The numbers may change without notice.”
How long does an EIN take by fax or mail?
The Instructions for Form SS-4 (Rev. December 2025) say an EIN can be received by fax generally within 4 business days under the Fax-TIN program, and say to complete Form SS-4 at least 4 to 5 weeks before an EIN is needed when applying by mail. The IRS Employer identification number page said an EIN applied for by mail arrives in approximately 4 weeks.
Is there a limit on how many EINs can be issued in a day?
The Instructions for Form SS-4 (Rev. December 2025) say EIN issuances are limited to one per responsible party, per day, and that the limitation applies to all requests for EINs whether online, telephone, fax, or mail. The IRS Get an employer identification number page and the IRS Employer identification number page state the limit in their own words.
Who is the responsible party on Form SS-4?
The Instructions for Form SS-4 (Rev. December 2025) say the “responsible party” is the person who ultimately owns or controls the entity or who exercises ultimate effective control over the entity. They say that, unless the applicant is a government entity, the responsible party must be an individual, and for trusts the responsible party is a grantor, owner, or trustor.
Can an EIN application be made by telephone?
When we checked on November 2, 2026, the Instructions for Form SS-4 (Rev. December 2025) said the IRS no longer issued EINs by telephone for domestic taxpayers and that only international applicants can receive an EIN by telephone. For international applicants they give 267-941-1099 (not a toll-free number), 6:00 a.m. to 11:00 p.m. (Eastern time), Monday through Friday.
Does the IRS charge for an EIN?
When we checked on November 2, 2026, the IRS Get an employer identification number page said: “Beware of websites that charge for an EIN. You never have to pay a fee for an EIN.”
Related form pages
- Form I-9 (2026): Employment Eligibility Verification, Edition and Document Lists
- IRS Form W-9: Lines, Exempt Payee Codes and Backup Withholding
- IRS Letter 147C (EIN Previously Assigned): How the IRS Says to Get One
- Form 2553, S corporation election
- Schedule C
- Form 8822-B, change of address or responsible party