A Practical Guide to Filling Out IRS Form W9

And Why Getting It Right Saves Headaches Later

I still remember the first time I came across a W-9.

I had just landed my first freelance gig, and the client sent over a PDF titled “W-9,” no context, no instructions. I had seen plenty of tax forms before, but this one came with questions: Who gets this? Do I send it to the IRS? What happens if I fill it out wrong?

I figured it out eventually, but it made me realize something:
Even simple forms can feel intimidating when you’re on your own.

If that sounds familiar, you’re not alone.

That’s why we created this guide, to take the guesswork out of the process and help you feel confident every step of the way.

1. What is Form W-9?

Form W-9 is a simple IRS form used in the United States to request the Taxpayer Identification Number (TIN) of a person or business.

It’s not filed with the IRS, it’s handed to the person or company that’s going to pay you.

If someone has asked you to fill one out, it means they’re likely going to report the payments they make to you to the IRS, and they need your information to do it correctly.

In short: W-9 = “Tell me how to report what I’m paying you.”

2. Who Needs to Fill Out a W-9?

• Independent contractors or freelancers
• Single-member LLCs
• Landlords receiving rent payments
• Individuals receiving prizes or awards
• Anyone earning non-employee income that may trigger a 1099

If you’re not a W-2 employee, chances are you’ve seen this form before, or you will.

3. Why It’s Important to Fill It Out Correctly

Incorrect or missing information can lead to:

• Backup withholding: 24% of your payments could be withheld if you don’t provide a correct TIN.
• IRS penalties: For incorrect or fraudulent information.
• Delays in payment: Companies may withhold payments until they receive a valid W-9.

Filling it out correctly means fewer surprises during tax season, for you and the person paying you.

4. Step-by-Step Breakdown (Key Sections)

Line 1: Your Name

Use your legal name as it appears on your tax return.

Line 2: Business Name or DBA

If you operate under a business name that’s different from your personal name, list it here.

Line 3: Federal Tax Classification

Check the appropriate box (Individual/Sole Proprietor, LLC, C Corp, S Corp, etc.).
For LLCs, pay close attention to how your business is taxed.

Lines 5 & 6: Address

Include the mailing address where you want to receive tax documents.

Part I: Taxpayer Identification Number (TIN)

Use your SSN if you’re an individual without a business name or EIN.
Use your EIN if you listed a business name or operate under a DBA.

The number you enter must match the name on Line 1.

Part II: Certification

Sign and date the form. No W-9 is valid without this.

5. Common Mistakes to Avoid

• Leaving the form unsigned
• Using a business name without an EIN
• Mismatched name and TIN
• Forgetting to update your W-9 if your tax classification changes

6. Final Tips

• You don’t need to submit this form to the IRS, just to the payer.
• Keep a copy for your records.
• If someone refuses to pay you until they get your W-9, that’s legal. They need it for IRS reporting.

Why We Care (and You Should Too)

At My Books and Taxes, we’ve helped hundreds of independent workers, small business owners, and law firms navigate tax season smoothly, and it all starts with small steps like completing a W-9 correctly.

If you’re unsure how to fill it out, or you’re onboarding contractors and want to get it right, we’ve got your back.

Prefer visuals? Check out our Instagram Post for a step-by-step breakdown of the form.

You’ve got this, and we’re with you every step of the way.