How to Apply for an EIN in Idaho: Step-by-Step

To apply for an EIN in Idaho, most eligible applicants can use the IRS online EIN tool. The EIN is federal, so there is no separate Idaho EIN application or Idaho-issued EIN. If the online application is approved, the IRS issues the number immediately. Applying directly to the IRS is free.

The key is to complete the steps in the right order. If you are creating an Idaho LLC, partnership, corporation, or tax-exempt organization, form the entity through Idaho’s SOSBiz system before requesting its EIN. Then gather the responsible party’s information, complete the IRS application in one session, and save the confirmation letter.

Determine your entity and online eligibility

Start by identifying the legal structure that will receive the EIN. The IRS application asks for the entity type, so an applicant should know whether the business is operating as a sole proprietorship, LLC, partnership, corporation, tax-exempt organization, or another recognized structure.

An Idaho LLC, partnership, corporation, or tax-exempt organization should be formed with the state before applying for its EIN. Idaho business entity filings are handled through the Secretary of State’s SOSBiz system. This order helps ensure that the name and legal structure used on the federal application match the entity that was created in Idaho. This state-formation step is not stated as a prerequisite for a sole proprietor.

For the IRS online tool, the principal place of business must be in the United States or a U.S. territory. The person submitting the application must be the responsible party or an authorized representative, and the applicant must have the responsible party’s Social Security number or Individual Taxpayer Identification Number.

Not every person seeking a business-related tax account is necessarily looking for the same number. An EIN is a federal identifier issued by the IRS, while Idaho tax and permit registrations are separate. For a broader comparison, see how to get a tax ID number in Idaho for a new business.

Gather the information before starting

Prepare the application details before opening the online tool because the session cannot be saved. At a minimum, be ready to identify the entity type and provide the responsible party’s SSN or ITIN.

The responsible party is central to the application. Make sure the identifying information entered for that person is accurate and consistent with the entity being presented to the IRS. If someone other than the responsible party will submit the application as a third-party designee, that designee must have signed authorization to apply.

It is also practical to have the entity’s formation details and business information close at hand. Review the legal name and entity structure before beginning rather than relying on memory. For a newly formed corporation, the federal identification process is discussed further on the corporation EIN page.

Plan to complete the online application without interruption. The IRS session expires after 15 minutes of inactivity, and an unfinished application cannot be saved for later. Choosing a time when the responsible party or authorized representative can review every entry in one sitting can help avoid restarting the process.

Apply for the Idaho business EIN step by step

1. Form the Idaho legal entity, if applicable. Complete the Idaho formation filing first when the applicant is an LLC, partnership, corporation, or tax-exempt organization formed in Idaho. Use the finalized legal structure when preparing the EIN application.
2. Confirm that the online method is available. The IRS online tool is available when the principal place of business is in the United States or a U.S. territory. Confirm that the person applying is the responsible party or an authorized representative and has the responsible party’s SSN or ITIN.
3. Open the IRS EIN tool. Apply directly through the IRS “Get an employer identification number” tool. The IRS does not charge a fee for a direct EIN application.
4. Select the entity type carefully. Choose the structure that corresponds to the applicant. Do not select a structure merely because it sounds similar to a trade name or business activity; use the legal form under which the business or organization operates.
5. Enter the responsible party’s information. Provide the requested SSN or ITIN and complete the remaining prompts. An authorized third-party designee should have the required signed authorization before applying.
6. Review the entries before submitting. Check the legal name, entity type, and responsible-party information while the session remains active. Because the application cannot be saved, corrections should be made before final submission when possible.
7. Submit and retain the confirmation. An approved online application receives the EIN immediately. Print the EIN confirmation letter after approval and preserve it with the organization’s important records.

EIN issuance is limited to one EIN per responsible party per day. That limit applies across online, telephone, fax, and mail application methods, so changing the submission method does not create another same-day issuance opportunity for the responsible party.

Use Form SS-4 if applying by fax or mail

An Idaho applicant who does not use the online tool may be able to submit Form SS-4 by fax or mail. These methods do not provide the same immediate result as an approved online application.

Fax application

An applicant whose principal business, office, agency, or legal residence is in one of the 50 states or the District of Columbia may fax Form SS-4 to 855-641-6935. When the applicant supplies a fax number, the IRS generally returns the EIN by fax within four business days. This is a general processing estimate, not a guaranteed completion deadline.

Mail application

For an applicant whose legal residence, principal place of business, or principal office or agency is in a state or the District of Columbia, mail the signed Form SS-4 to:

The Form SS-4 instructions say to apply at least four to five weeks before the EIN is needed and state that receipt by mail takes approximately four weeks. Because this timing is an estimate, allow room for mailing and processing rather than planning around an exact delivery date.

What to do after receiving the EIN

Save the EIN confirmation letter in a secure place. The EIN itself is only one part of setting up a business, and receiving it does not complete separate Idaho registrations that may apply to the operation.

Idaho uses its Idaho Business Registration process for applicable state tax and employee-related permits. Applicants should have their EIN available if they have one. That state registration is separate from obtaining the federal EIN, so completing one process should not be treated as completing the other. Businesses evaluating a sales-related registration can also review information about an Idaho sales tax number.

Keep the entity’s records consistent when using the EIN in later registrations and business paperwork. Refer to the confirmation letter rather than retyping the number from memory, and limit access to people who need it for legitimate business administration.

Practical Idaho examples

A new Idaho LLC

Suppose an owner intends to operate through a newly created Idaho LLC. The owner first completes the LLC formation through SOSBiz. After the entity exists, the responsible party can use the IRS online tool, provided the online eligibility conditions are met. If approved, the EIN is issued immediately, and the owner should print the confirmation letter.

A sole proprietor seeking an EIN

A sole proprietor does not complete an LLC or corporation formation step merely to use the EIN application. The applicant should identify the entity correctly as a sole proprietorship and be prepared to provide the responsible party’s SSN or ITIN. The business can then address any separate Idaho tax or employee-related permit registrations that apply to its activities.

An authorized representative filing for a business

If an accountant or another representative submits the online application instead of the responsible party, the representative must be authorized and must have the responsible party’s SSN or ITIN. A third-party designee also needs signed authorization to apply. The representative should arrange that authorization and gather the entity information before opening the time-limited IRS session.