On Form SS-4, the legal name and the trade name go on separate lines and mean different things. Line 1 is your legal name, entered exactly as it appears on the document that created the entity or, for a sole proprietor, on your Social Security card. Line 2 is the optional trade name or “doing business as” (DBA) name you operate under publicly, and it stays blank if you don’t use one. The IRS treats Line 1 as your tax identity and Line 2 as a secondary label.
What Goes on Line 1
Line 1 must match your founding paperwork. What that means depends on the entity:
- Sole proprietors enter their own first name, middle initial, and last name. Not the business name. The IRS instructions say not to use abbreviations or nicknames.1Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025)
- Corporations enter the corporate name exactly as it appears in the charter or articles of incorporation, including any suffix like Inc., Corp., or PC.1Internal Revenue Service. Instructions for Form SS-4 (Rev. December 2025)
- Partnerships enter the legal name from the partnership agreement.
- Trusts enter the trust name exactly as it appears on the trust instrument.
- Estates enter the estate’s name. If the estate has no formal legal name, use the decedent’s name followed by “Estate.”2Internal Revenue Service. Instructions for Form SS-4 (12/2025)
The common thread: Line 1 has to match whatever document brought the entity into existence. For a person, that’s the Social Security card. For a corporation, the articles filed with the state. For a trust, the trust instrument. Any discrepancy between Line 1 and those records can trigger a rejection or create tracking problems with the IRS later.
What Goes on Line 2
Line 2 is labeled “Trade name of business (if different from name on line 1).”3Internal Revenue Service. Form SS-4 – Application for Employer Identification Number Use it for the public-facing name your customers see when it differs from the legal name on Line 1. A corporation legally registered as “Greenfield Holdings LLC” that runs a coffee shop called “Morning Grounds” would put the LLC name on Line 1 and “Morning Grounds” on Line 2.
Sole proprietors often use Line 2 for their business name, because their personal name already occupies Line 1. Corporations and LLCs whose legal name is the same as their business name leave Line 2 empty. If you don’t operate under a separate name, leave it blank. That’s the normal case.
What a DBA on the Application Does and Doesn’t Do
Putting a trade name on Line 2 is a label, not a registration. A DBA carries no legal weight for federal tax purposes. It doesn’t create a separate tax entity, doesn’t offer liability protection, and doesn’t give you any ownership rights to the name. Registering a DBA at the state or county level is a separate process from applying for an EIN, and the two don’t interact. Listing a trade name on your EIN application reserves nothing and protects nothing.4U.S. Small Business Administration. Choose Your Business Name
Your EIN is tied to the Line 1 name in IRS systems. The trade name is stored, but it isn’t your tax identity. Every return, information return, and payment gets matched against Line 1.
Why the Line 1 Name Has to Be Right
A wrong or inconsistent legal name creates problems that only surface later. The IRS uses Line 1 to verify that your entity exists and to match filings to it. A mismatch can delay return processing and generate notices.
The concrete cost shows up in information returns. Under Section 6721, filing an information return with an incorrect name or taxpayer identification number triggers penalties that grow the longer the error goes uncorrected. For returns due in 2026, the penalty runs $60 per return if corrected within 30 days, $130 if corrected by August 1, and $340 per return after that. Intentional disregard of the filing requirements raises the penalty to $680 per return with no cap.5Internal Revenue Service. Information Return Penalties
Small businesses with gross receipts of $5 million or less get lower annual caps, though the per-return amounts are the same. The $340-tier annual maximum, for example, tops out at $1,366,000 for small businesses and $4,098,500 for larger entities.6Internal Revenue Service. IRM 20.1.7 Information Return Penalties Filing a stack of 1099s under a Line 1 name that doesn’t match IRS records adds up quickly.
Changing the Name After You Have the EIN
A name change alone doesn’t require a new EIN. If you change your business name or address, your existing EIN stays with you.7Internal Revenue Service. When to Get a New EIN But the IRS needs to be told, and the method depends on the entity:
- Corporations that haven’t filed the current-year return check the name change box on the return (Line E, Box 3 on Form 1120). Those that already filed send a written notification to the address where the return was filed.8Internal Revenue Service. Business Name Change
- Partnerships do the same: check the box on Form 1065 (Line G, Box 3) if the return isn’t filed yet, or write in if it is.
- Sole proprietors write to the IRS at the address where they file their return. The notification must be signed by the owner or an authorized representative.8Internal Revenue Service. Business Name Change
If you want confirmation that the change was processed, ask for it in the notification. The IRS won’t send one on its own.
A change to your DBA alone, with the underlying legal name unchanged, doesn’t affect the EIN record on Line 1. That’s a state or county filing.
Before You Submit
Pull out the founding document before you fill in Line 1. For a corporation, that’s the articles of incorporation, with the exact name and suffix. For a sole proprietor, the Social Security card, with no nickname substituted. For a trust or estate, the trust instrument or the decedent’s name plus “Estate.” Then decide whether Line 2 applies: if you operate publicly under a name different from Line 1, put it there; otherwise leave it blank. Verifying the Line 1 name against the source document is the cheapest compliance step you’ll take on the whole application.