How to Get an EIN for Your Solo Founder Business in Arizona (2026)

As a solo founder in Arizona, you're building something from the ground up. An Employer Identification Number (EIN) is a crucial step, acting as your business's Social Security number. This guide walks you through obtaining an EIN for your Arizona-based solo venture in 2026, ensuring you're set up for success. Lovie can streamline this process, giving you more time to focus on growing your business.

What is an EIN?

An EIN is a unique nine-digit tax identification number assigned by the IRS to business entities operating in the United States. It’s used to identify your business for tax purposes, enabling you to hire employees, open business bank accounts, and file business taxes. Even as a solo founder, you'll likely need one if you're not operating as a sole proprietorship.

How to Apply for an EIN

  1. Determine Your Eligibility: Ensure your solo founder business structure requires an EIN. Single-member LLCs and corporations generally need one. Sole proprietorships may need one if they hire employees or operate as a corporation.
  2. Choose Your Business Structure: Decide on your business structure (LLC, S-Corp, etc.). This decision impacts your tax obligations and liability. Arizona LLCs require publication of formation documents, so factor that into your decision.
  3. Prepare Form SS-4: Gather the necessary information to complete IRS Form SS-4, the Application for Employer Identification Number. This includes your business name, address, and the reason for applying.
  4. Submit Your Application: Apply for your EIN online through the IRS website. The online application is the fastest method and is generally processed immediately.
  5. Receive Your EIN: Upon successful submission, you'll receive your EIN immediately. Download and save the confirmation notice (Form CP 575 or a digitally signed PDF letter).
  6. Notify Arizona State Agencies (If Applicable): Depending on your business activities, you may need to notify the Arizona Department of Revenue or other state agencies of your EIN. This is especially important for transaction privilege tax (TPT).

Start your formation with Lovie — $20/month, everything included.