5 Common Mistakes on Form SS-4 (And How to Avoid Them)

Form SS-4 looks simple — it's just one page. But small mistakes can delay your EIN by weeks. Here are the five most common errors.

1. Legal name doesn't match formation docs

The name on Line 1 of your SS-4 must be identical to the name on your Articles of Organization or Certificate of Formation. If your LLC was formed as "TechCo Solutions, LLC" with a comma, include the comma. If it says "Inc." not "Incorporated," use "Inc."

The IRS will reject applications where the name doesn't match what's on file with your state of formation.

2. Listing the company as its own responsible party

Line 7a asks for the "responsible party." Many people write their company name here. The IRS explicitly requires a person — an individual with an SSN, ITIN, or EIN. For single-member LLCs, this is typically the sole member.

3. Checking the wrong entity type

Line 9a has multiple entity type options. Foreign-owned LLCs that have elected to be taxed as corporations (via Form 8832) should check "Corporation." Single-member LLCs that haven't made an election are "disregarded entities" — check "Other" and specify.

4. Wrong date for "business started"

Line 16 asks when the business started or was acquired. This is the date your entity was officially formed with the state — not the date you started doing business, and not the date you're filling out the form.

5. Using a PO Box when not allowed

Lines 4-5 ask for mailing and street addresses. The street address (Lines 5a-5b) cannot be a PO Box. Your mailing address can be. If you're using a registered agent, use their physical office address for the street address.

How UFF helps

UFF validates your inputs as you fill, flagging required fields and formatting issues before you generate the PDF. This catches most of these mistakes before they reach the IRS.