Starting a business comes with a long checklist, but one of the first—and most important—items is obtaining an Employer Identification Number (EIN) from the IRS. Think of an EIN as the Social Security number for your business. It identifies your entity for tax purposes, allows you to hire employees, open business bank accounts, file returns, and stay compliant from day one.

The good news? Getting an EIN is free, fast, and easier than many new business owners expect.

What Is an EIN, Exactly?

An Employer Identification Number is a unique nine-digit number assigned by the IRS to businesses and certain trusts, estates, and organizations. If you plan to operate anything beyond a simple sole proprietorship with no employees, you’ll likely need an EIN.

You also need an EIN if you plan to:

• Open a business bank account
• Hire employees
• Start an LLC or corporation
• Form a partnership
• Create a trust or estate
• Buy or sell a business
• Apply for certain licenses and permits

Treat it as your official identifier whenever you interact with the IRS or financial institutions.

How Do You Get an EIN? The Four Ways

The IRS offers multiple options to apply, but the method you choose determines how quickly you receive your number.

1. Apply Online (Fastest & Recommended)

If your principal business is located in the U.S. or its territories, you can apply online through the IRS EIN Assistant.

• Takes about 10 minutes
• You receive your EIN immediately
• Must complete the application in one sitting
• The IRS issues a downloadable confirmation letter (CP 575) on the spot

This is the preferred method for most new business owners.

2. Apply by Fax

If you prefer or need a physical form, complete Form SS-4, then fax it to the IRS.

• Processing time: about 4 business days
• The IRS faxes back your EIN confirmation once processed

3. Apply by Mail

You can mail Form SS-4, although this is the slowest option.

• Processing time: about 4–5 weeks

4. International Applicants (No U.S. Principal Office)

If you’re outside the U.S. and still need an EIN—for example, to open a U.S. branch or conduct taxable activities—you can call the IRS directly.

• Phone number: 267-941-1099 (not toll-free)
• Processing occurs during the call

Is There a Fee?

No. Obtaining an EIN is free. If a website attempts to charge you, you’re not on the official IRS website.

Do All Businesses Need an EIN?

Not every sole proprietor needs one, but most businesses benefit from having one anyway.

You must obtain an EIN if you:

• Have employees
• Operate as an LLC, corporation, or partnership
• Withhold taxes on income (like for a non-resident)
• Have a Keogh retirement plan
• File excise or employment returns
• Form a business bank account (most banks require it even for single-member LLCs)

For many sole proprietors, obtaining an EIN is a good idea simply to avoid using your Social Security number with vendors, contractors, or clients.

How Long Does It Take?

• Online: Minutes
• Fax: Around 4 days
• Mail: Weeks
• International phone: During the call

If you’re planning to form an entity, hire employees, or open a business bank account soon, it’s best to obtain your EIN early in the process.

Common Mistakes to Avoid

• Applying more than once. The IRS may flag duplicate applications.
• Choosing the wrong entity type on Form SS-4 (especially important for LLCs).
• Using unverified third-party websites that charge unnecessary fees.
• Submitting incomplete applications—especially via fax or mail—which causes delays.

Bottom Line

Getting an EIN is one of the simplest steps in starting a business. It’s free, quick, and opens the door for essential operational tasks like payroll, banking, and compliance. Whether you’re forming a new LLC, running a growing side business, or preparing for future expansion, securing your EIN early keeps your business on solid ground from day one.

If you ever need help understanding entity types, preparing Form SS-4, or getting your business set up for tax and legal success, professional guidance is just a call away.

At Dino Tax Co, we help clients navigate tax matters ranging from unfiled returns to IRS letters and levies and everything in between with clarity and confidence. If you’d like guidance on your situation, schedule a consultation today. Call or text (713) 397-4678 or email davie@dinotaxco.com. We’re here to help you take the next step.