How to Fill Out Form SS-4 (Line by Line)
The form runs a single page. Most businesses finish in about ten minutes with the right details on hand. The official form ss-4 instructions run long, so here's the working version, along with the mistakes that cause rejections.
Business Name and Address (Lines 1 to 6)
Line 1 takes the legal name exactly as it appears on your formation documents. Line 2 is the trade name or DBA, and only if it differs. Lines 4 and 5 cover the mailing and physical addresses.
Watch this one. The IRS rejects a PO box on the street address lines, so use a physical location even if your mail goes somewhere else.
Responsible Party and Entity Type (Lines 7 to 10)
Line 7 names the responsible party and their SSN or ITIN. Leaving that field blank is the single most common reason an application stalls.
Line 9a is the entity-type checkbox, and it's where filers slip. A single-member LLC that hasn't elected corporate status checks the Other box on line 9a and writes "disregarded entity" in the space provided. There is no dedicated disregarded-entity checkbox. Line 10 asks why you're applying, whether that's hiring employees, starting a new business, or banking.
Signature and Final Checks
An unsigned form is a dead form. Sign it, date it, and add a daytime phone number the IRS can call.
Before it goes out, confirm three things: the entity box matches your actual structure, the responsible party is a named individual, and no PO box sits on the address lines. The IRS ss4 instructions cover edge cases like trusts and estates if yours is unusual.
How to Submit Form SS-4
Four channels will get your completed application to the IRS. Every competing page lists all four. Choosing between them is the part that actually matters, so here it is in plain terms.
- US-based responsible party with an SSN or ITIN: apply online and you'll usually have the EIN the same day.
- No US SSN or ITIN, or you're applying on someone else's behalf: fax is the fastest paper route, roughly four business days with a return fax number.
- No deadline pressure: mail works fine, but budget four to five weeks from the day your SS-4 form goes out.
- International applicants: the IRS phone line handles applications from outside the US.
The online tool runs Monday through Friday, 7 a.m. to 10 p.m. ET. It isn't open around the clock, which catches out anyone who sits down to do paperwork at midnight.
One practical warning. The session expires after 15 minutes of inactivity, and there's no save button. Draft your legal name, address, entity type, and reason for applying somewhere else first, then paste them in. An interruption means restarting the ss-4 online application from the top.
Create Your SS4 Form Online
A blank IRS PDF makes you retype everything and catches nothing. Our SS4 generator walks the same fields in order, flags a missing responsible party or a PO box before you submit, and outputs a clean, printable document.
You preview the result first and pay only at download, with no subscription. Once the EIN lands and you start paying people, the same business details carry into employee pay documentation, and our pay stub templates keep the formatting consistent from the first payroll run. Getting the withholding lines right matters just as much, so it helps to know how payroll deductions work before your first run.
Your EIN Confirmation Letter (CP 575 and 147C)
When the IRS issues your EIN, it sends a CP 575 notice. That's your original IRS EIN letter, and it's the document banks, lenders, and payroll providers ask to see.
Here's the catch. The IRS issues CP 575 exactly once and won't mail a replacement. Eligible users can download a digital copy through their IRS business account; otherwise you call the IRS Business and Specialty Tax Line and request a 147C letter, which serves the same purpose.
If yours is gone, call the IRS Business & Specialty Tax Line and request a 147C letter instead. It's an official replacement that verifies the same number, and it's accepted anywhere the original would be. Expect to verify your identity as the responsible party first.
Treat this as a recordkeeping job rather than a paperwork errand. Store the IRS SS-4 confirmation letter where your payroll and banking records already live, because the next person who needs that SS4 letter may not be you.
What Does an EIN Number Look Like?
An EIN uses the format XX-XXXXXXX: a two-digit prefix, a hyphen, then seven more digits, nine digits total. It looks similar to a Social Security number, but the grouping differs, since an SSN runs XXX-XX-XXXX. The prefix reflects where the IRS issued the number, not your location.
So a valid ein format never carries the SSN's second hyphen. If a vendor sends you nine digits grouped the wrong way, ask before you file anything with it. Mismatched IDs are a routine source of rejected information returns.
When Does Your Business Need a New EIN?
You need a new EIN when the business structure changes: incorporating a sole proprietorship, adding partners, or certain ownership and bankruptcy changes. You do not need one for a name change, an address change, or opening additional locations. Filing an unnecessary second SS-4 creates duplicate EINs.
This is where owners quietly create expensive problems. Incorporating or bringing on a partner changes the entity itself, so the IRS wants a new number. Rebranding doesn't. Relocating doesn't. Opening a second location doesn't either.
File a second SS4 form you never needed and you've now got two EINs attached to one business. That surfaces later as mismatched filings and IRS notices, and it takes months to unwind.
What's New on the 2026 SS4 Form
Use the December 2025 revision. It's the current IRS SS4 form for 2026 filings, and the One Big Beautiful Bill Act brought no SS-4-specific changes for the 2025 tax year.
That sounds like a non-event, and mostly it is. It matters because stale copies circulate. Some template sites still serve pages last reviewed back in 2023, so check the revision date printed on any blank IRS Form SS4 you download. Cross-check yours against the SS4 form IRS posts at irs.gov, and confirm the revision line reads December 2025 before anything goes out.
Which Version of Form SS-4 Do You Need?
There is no annual Form SS-4. The IRS does not reissue it every year the way it reissues Form 941 or Form 940, so there is no "2025 form" and no "2026 form" to pick between. The current revision is December 2025, and the one before it was December 2023. When a search reads "SS-4 2026," the year refers to when you happen to be applying, not to a separate document.
The form also carries no deadline of any kind. You file it when the business needs the number, not against a calendar. The only timing rule that matters is practical: apply early enough that the EIN is in hand when a return, a statement, or a deposit needs one. If the number still has not arrived when a return comes due, write "Applied For" and the date you applied in the space where the EIN goes, then file on time anyway.
One related trap for payroll teams. When the responsible party changes later, that update runs on Form 8822-B within 60 days. It never runs on a second SS-4.