EINの取得

Detailed explanation of EINの取得 based on official information from 各州州務長官事務所・IRS. Permanent Residency (Green Card)

Published: January 12, 2026

Employer Identification Number (EIN): A Complete Guide

1. Overview

An Employer Identification Number (EIN), also known as a Federal Tax Identification Number, is a unique nine-digit number assigned by the Internal Revenue Service (IRS) to business entities operating in the United States. The EIN serves as the business equivalent of a Social Security Number for individuals and is essential for tax administration, banking, hiring employees, and establishing business credit. Obtaining an EIN is a fundamental step in formalizing most business structures and ensures compliance with federal tax requirements.

2. Applicable Objects & Scenarios

An EIN is required for various entities and situations, including but not limited to:

  • Business Entities: Corporations, Limited Liability Companies (LLCs), partnerships, and sole proprietorships that have employees.
  • Employers: Any business that hires employees, including household employers.
  • Tax-Filing Entities: Estates, trusts, non-profit organizations, farmers' cooperatives, and plan administrators.
  • Specific Situations: Opening a business bank account, applying for business licenses and permits, filing tax returns for the business, and withholding taxes on income (other than wages) paid to a non-resident alien.
  • Sole Proprietors without Employees: While not always mandatory, obtaining an EIN is highly recommended to avoid using your personal Social Security Number on business documents, enhancing privacy and security.

3. Core Conclusions

  • An EIN is a mandatory federal identifier for most businesses, especially those with employees.
  • The primary and most efficient method to obtain an EIN is through the IRS's free online application.
  • The application process requires the identification of a "responsible party," who must be a natural person (not an entity) with a valid Taxpayer Identification Number (SSN, ITIN, or EIN).
  • There is no cost to apply for an EIN directly through the IRS.
  • An EIN is permanently assigned to the entity; however, you may need a new one if the business structure or ownership changes significantly.

4. Procedures & Steps

Step 1: Preparation

Before applying, gather the necessary information about your business and the responsible party:

  • Legal Name of Entity: The official name of your business as it appears on formation documents.
  • Trade Name (DBA): If applicable.
  • Mailing Address and Physical Location.
  • Responsible Party Information: The name, Social Security Number (SSN), Individual Taxpayer Identification Number (ITIN), or existing EIN of the principal officer, general partner, grantor, or owner.
  • Type of Entity: (e.g., Sole Proprietorship, Partnership, Corporation, LLC).
  • Reason for Applying: (e.g., Started a new business, Hired employees, Banking purposes).
  • Details about Activities: Principal business activity and the number of employees expected in the next 12 months.

Step 2: Application & Submission

The IRS provides several application methods, with the online application being the preferred and fastest option.

  • Online Application: Complete the interview-style application on the IRS website. This service is available Monday through Friday, 7 a.m. to 10 p.m. EST. Upon completion, you receive your EIN immediately.
  • Fax: Complete Form SS-4 and fax it to the appropriate IRS service center. You will receive your EIN via fax within approximately one week.
  • Mail: Complete Form SS-4 and mail it to the IRS. This is the slowest method, taking up to several weeks.
  • Telephone (International Applicants Only): Applicants outside the U.S. without a legal U.S. residence may apply by calling 267-941-1099 (not a toll-free number).

Step 3: Review & Confirmation

  • Online/Fax: You will receive your official EIN confirmation (CP 575 Notice or a fax confirmation) immediately or shortly after submission. Save this document securely.
  • Verification: You can verify your EIN and business name with the IRS for tax purposes after it has been assigned.
  • Record Keeping: Provide your EIN to your bank, state agencies, and when filing business tax returns.

5. Frequently Asked Questions (FAQ)

Q1: Is there a fee to get an EIN from the IRS? A: No. The IRS does not charge any fee to assign an EIN. Be cautious of third-party websites that charge for this service; you can apply for free directly on IRS.gov.

Q2: Can I use my SSN instead of an EIN for my business? A: A sole proprietor with no employees may use their SSN for federal taxes. However, obtaining an EIN is strongly advised to protect your personal identity, establish business credit, and meet requirements for business bank accounts or licenses.

Q3: How long does it take to get an EIN? A: Through the online application, you receive your EIN immediately upon verification. Fax applications take about a week, while mail applications can take several weeks.

Q4: I lost my EIN confirmation letter. How do I get it again? A: If you cannot find your EIN, you can call the IRS Business & Specialty Tax Line at 800-829-4933. The representative will ask for identifying information to provide your number. The IRS will not re-issue the CP 575 notice, but you can request a 147C letter as proof of your EIN.

Q5: Do I need a new EIN if I change my business name or location? A: No. A change in business name or location does not require a new EIN. You must inform the IRS of the change by updating your information via a letter or the appropriate tax return.

Q6: When does a business need a new EIN? A: You typically need a new EIN if the legal structure or ownership of your business changes. Examples include converting a sole proprietorship to an LLC, forming a corporation from a partnership, or after a bankruptcy reorganization.

Q7: Can an EIN be used immediately? A: Yes. Once you receive your EIN through the online system, it becomes part of the IRS's permanent records immediately, and you can begin using it right away for most purposes.

6. Risks & Compliance

  • Accuracy is Critical: Ensure all information on the SS-4 form is accurate. Incorrect information can delay processing and cause issues with tax filings.
  • One EIN Per Entity: Each business entity should have only one EIN. Do not apply for multiple EINs for the same entity.
  • Responsible Party: You must have a valid SSN, ITIN, or EIN to be the responsible party. The IRS will not assign an EIN without this.
  • Third-Party Services: While you can use a tax professional or service to apply on your behalf, ensure they are reputable. You are ultimately responsible for the information provided.
  • State Requirements: An EIN is a federal number. You must also check with your state revenue or taxation department for state-level tax ID requirements.
  • Disclaimer: This guide provides general information. Tax laws and procedures can change. For the most current information and advice specific to your situation, consult the official IRS resources or a qualified tax professional.

7. References & Sources

8. Related Topics

  • Forming an LLC in the USA
  • U.S. Business Tax Filing Requirements
  • State Sales Tax Permits
  • U.S. Payroll and Hiring First Employee
  • Business Bank Account Requirements
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