How EINs Are Used by the IRS

Dec. 13, 2025, 6:12 p.m.
An Employer Identification Number (EIN) is a unique nine-digit number issued by the IRS to identify a business or organization. Here’s how the IRS uses EINs in practice:
IRS EIN Online

1. Business Identification

The IRS uses an EIN to uniquely identify a business entity, similar to how an SSN identifies an individual. It links all tax records to the correct company.

2. Tax Filing and Processing

EINs are used to process and track:

  • Business income tax returns (Forms 1120, 1120-S, 1065)

  • Employment tax returns (Forms 941, 940)

  • Excise tax returns

  • Information returns (Forms 1099, W-2)

3. Payroll and Employment Taxes

If a business has employees, the EIN allows the IRS to:

  • Monitor payroll tax withholdings

  • Track Social Security, Medicare, and federal income tax payments

  • Enforce compliance with employment tax laws

4. Business Account Management

The IRS uses EINs to maintain business tax accounts, recording:

  • Tax payments

  • Penalties and interest

  • Credits and refunds

  • Filing history

5. Entity Classification

EINs help the IRS determine:

  • Business structure (LLC, corporation, partnership, nonprofit)

  • Tax classification (disregarded entity, partnership, corporation)

  • Whether the entity is taxable or tax-exempt

6. Compliance and Audits

During audits or investigations, the EIN is the primary reference number used to:

  • Review filings and financial activity

  • Match reported income with third-party reports

  • Identify underreporting or noncompliance

7. Information Reporting Matching

The IRS matches EINs against:

  • 1099 forms issued by clients or vendors

  • W-2 forms submitted by employers
    This helps ensure income and wages are reported accurately.

8. Business Tax Payments

All federal tax payments made through EFTPS or IRS Direct Pay are tied to the EIN, ensuring payments are credited to the correct business.

9. Communication and Notices

The IRS uses the EIN when sending:

  • Tax notices and letters

  • Requests for information

  • Refund confirmations

  • Penalty or compliance warnings

10. Fraud Prevention and Enforcement

EINs help the IRS:

  • Detect identity theft and tax fraud

  • Prevent misuse of business identities

  • Enforce federal tax laws across industries

11. Coordination With Other Agencies

The EIN is also used to share information with:

  • State tax authorities

  • Department of Labor

  • Social Security Administration
    This supports consistent enforcement across government agencies.

12. Long-Term Record Keeping

The IRS maintains EIN-based records even after a business closes, ensuring historical data remains accessible for audits or legal matters.

 

https://www.irs.gov/charities-non-profits/exempt-organization-types