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

As co-founders in California, securing an Employer Identification Number (EIN) is a crucial step in establishing your business. This guide provides a clear roadmap for obtaining an EIN in 2026, tailored to the specific needs and challenges of co-founder partnerships. Lovie can streamline this process, handling the EIN application seamlessly as part of your company formation.

What is an EIN?

An Employer Identification Number (EIN) is a unique nine-digit tax ID assigned by the IRS to business entities. It's essentially a Social Security number for your business, used for tax reporting and identification purposes.

How to Apply for an EIN

  1. Determine Your Business Structure: Decide whether your co-founder business will be an LLC, C-Corp, or S-Corp. This choice impacts your tax obligations and the EIN application process. For co-founders, LLCs and C-Corps are common, with C-Corps preferred for venture capital fundraising.
  2. Gather Required Information: Collect essential information, including the legal names and addresses of all co-founders, the business name, and the reason for applying for the EIN. You'll also need to provide the principal business activity.
  3. Apply Online via the IRS Website: The easiest and fastest way to obtain an EIN is through the IRS website. The online application is available 24/7 and is generally processed immediately.
  4. Complete Form SS-4: Whether applying online or by mail/fax, you'll need to complete Form SS-4, Application for Employer Identification Number. The online application guides you through this process.
  5. Submit Your Application: If applying online, simply submit the completed form electronically. If applying by mail or fax, send the completed Form SS-4 to the appropriate IRS address or fax number.
  6. Receive and Store Your EIN: Upon successful application, you'll receive your EIN. For online applications, this is typically provided immediately. For mail/fax applications, it may take several weeks.

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