How to Get an EIN for Your Co-Founder Pair Business in Illinois (2026)

Starting a business with a co-founder in Illinois is an exciting venture! To operate legally and manage your finances effectively, you'll need an Employer Identification Number (EIN). This guide walks you through obtaining an EIN for your co-founder business in Illinois in 2026, ensuring you're set up for success. Lovie streamlines this process, making company formation simple.

What is an EIN?

An Employer Identification Number (EIN) is a unique nine-digit number assigned by the IRS to identify your business entity. Think of it as a Social Security number for your business. It's essential for various activities, including opening a bank account, hiring employees, and filing taxes. For Illinois co-founder businesses, it's a crucial step in establishing a legitimate and compliant operation.

How to Apply for an EIN

  1. Determine Your Business Structure: Decide on your business structure (LLC, Partnership, S-Corp, C-Corp). For co-founders in Illinois, LLCs and S-Corps are popular choices due to their flexibility and tax advantages. Consider the long-term implications for equity distribution and fundraising.
  2. Prepare Form SS-4: Complete IRS Form SS-4, Application for Employer Identification Number. This form requires information about your business, including its legal name, address, and the responsible party (typically one of the co-founders).
  3. Submit Your Application: You can apply for an EIN online through the IRS website, by fax, or by mail. The online application is the fastest method and is generally recommended.
  4. Provide Required Information: Be prepared to provide detailed information about your Illinois business, including the reason for applying for the EIN, the date the business was started, and the principal business activity.
  5. Review and Confirm: Carefully review all the information you've entered on Form SS-4 before submitting it to the IRS. Errors can cause delays or even rejection of your application.
  6. Receive Your EIN: If you apply online, you'll typically receive your EIN immediately. If you apply by fax or mail, it can take several weeks. The IRS will send you a confirmation notice (Form CP 575) with your EIN.

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