How to Apply for an EIN in South Dakota: New Business Guide

To apply for an EIN for a new South Dakota business, first complete any required entity formation with South Dakota, then choose an IRS application method. The IRS issues EINs; South Dakota does not run the EIN application process. For an eligible applicant, the fastest route is usually the IRS portal named “Apply for an Employer Identification Number (EIN) Online.” The online application is completed in one session and, if approved, provides the EIN immediately.

Before starting, decide who will be listed as the responsible party, confirm the business’s legal name and structure, and gather that person’s Social Security number or ITIN if applying online. The IRS does not charge a fee for obtaining an EIN directly from it.

Complete South Dakota Formation Before Applying

If the business will be an LLC, partnership, corporation, or tax-exempt organization, form the entity through South Dakota before requesting its EIN. Applying for the EIN before completing formation may delay the EIN application. South Dakota’s Secretary of State Business Services Online portal supports electronic formation of new businesses and electronic filing of Articles, but that state portal does not issue EINs.

This ordering helps keep the federal application aligned with the entity’s state formation record:

1. Choose the business’s legal structure.
2. Complete the applicable South Dakota entity formation.
3. Confirm the exact legal name shown on the formation record.
4. Identify the responsible party.
5. Select the online, fax, or mail EIN application method.

Owners still working through formation can use the South Dakota LLC formation checklist to organize that stage before moving to the EIN application.

Choose the Right Path for Your Situation

You have already formed a South Dakota entity

Use the entity’s completed formation information when preparing the EIN application. Enter the legal name and entity type carefully rather than relying on a planned name, trade name, or DBA. This is also the point to identify the individual who will serve as the responsible party for the EIN record.

You are eligible to apply online

The IRS online EIN tool may be used when the principal place of business is in the United States or a U.S. territory and the applicant is the responsible party or an authorized representative. The applicant must have the responsible party’s Social Security number or ITIN.

The online tool is designed to be completed in one session. It expires after 15 minutes of inactivity, so gather the business and responsible-party information before opening it. If the application is approved, the EIN is issued immediately.

You cannot or do not want to use the online tool

A South Dakota applicant may submit a completed Form SS-4 by fax or mail. For fax filing, send the form to 855-641-6935 and provide a return fax number. The IRS states that fax applicants generally receive the EIN within four business days.

For mail filing, send a signed and dated Form SS-4 to:

The IRS instructs mail applicants to apply four to five weeks before the EIN is needed and says the EIN arrives by mail in approximately four weeks. Domestic taxpayers cannot obtain an EIN by telephone; telephone applications are limited to international applicants.

Information to Prepare

Preparation matters most for the online method because the session can expire. Use the table below as an application worksheet rather than beginning the application while key decisions are unresolved.

An EIN is only one possible identification or registration item for a new company. The guide to getting a tax ID number in South Dakota explains how to distinguish tax-ID questions more broadly. Businesses selling taxable products or services may also need to investigate a separate South Dakota sales tax number.

Apply Online, by Fax, or by Mail

Online application

1. Verify that the business’s principal place of business is in the United States or a U.S. territory.
2. Confirm that the applicant is the responsible party or an authorized representative.
3. Have the responsible party’s Social Security number or ITIN ready.
4. Open the IRS “Apply for an Employer Identification Number (EIN) Online” portal only when prepared to finish.
5. Complete the application without allowing the session to remain inactive for 15 minutes.
6. If approved, retain the EIN and the confirmation provided at the end of the session.

The IRS charges no fee for an EIN obtained directly from it. A request for payment does not represent an IRS EIN issuance fee, although a separate service provider may charge for its own assistance.

Fax application

Complete Form SS-4 and review it before transmission. Include a return fax number, then fax the form to 855-641-6935. This method avoids the single-session limitation of the online tool, but the EIN is not issued immediately. The IRS describes the general fax turnaround as four business days.

Mail application

Complete, sign, and date Form SS-4 before mailing it to the Cincinnati EIN Operation address. Build mailing and IRS handling time into the business plan: the IRS advises applying four to five weeks before the EIN is needed and estimates that the EIN will arrive by mail in approximately four weeks.

Avoid Delays and Know What Happens Next

Several preventable issues can disrupt an EIN application. Starting before forming a South Dakota legal entity can create a sequencing problem. Entering the online portal without the responsible party’s SSN or ITIN can leave the applicant unable to complete the eligibility requirements. Pausing too long can cause the online session to expire, while expecting to obtain a domestic EIN by telephone leads to an unavailable application route.

Another limitation applies regardless of how applications are submitted: the IRS limits EIN issuance to one EIN per responsible party per day. Switching from the online tool to fax or mail does not avoid that all-method limit.

Before submitting, use this decision checklist:

• Has the LLC, partnership, corporation, or tax-exempt organization been formed through South Dakota?
• Are the legal name and business structure settled?
• Has the responsible party been identified?
• For an online application, is the principal place of business in the United States or a U.S. territory?
• Is the online applicant the responsible party or an authorized representative?
• Is the responsible party’s Social Security number or ITIN available?
• Can the online application be finished in one session without 15 minutes of inactivity?
• Has the responsible party already received an EIN that day?
• If filing by fax, has a return fax number been provided?
• If filing by mail, is Form SS-4 signed and dated, and has sufficient lead time been allowed?

After an EIN has been issued, keep the business’s federal record current. Use Form 8822-B to report a change to the responsible party, address, or location. A responsible-party change must be reported within 60 days. Changes to licensing or sales-tax registrations may involve separate processes; the overview of South Dakota business license requirements can help owners distinguish those obligations from the federal EIN application.