Form SS-4 for LLC: Line by Line, and Where It Fails

The screen that ends a failed EIN application does not tell you what went wrong. It says the IRS is unable to provide you with an EIN through this online assistant, gives a phone number, and asks you to have your information ready and mention a reference number. Then it throws away everything you typed. The Internal Revenue Manual tells the assistor on the other end of that phone number to say so out loud: advise taxpayer IRS does not save this information (IRM 21.7.13.3.4.1, page last reviewed 2 September 2026, read 16 September 2026).

That is the reason to treat this as a form even when you are filling it in as a web session. The assistant asks the same questions as Form SS-4, and the answers that break one break the other. Both the form and its instructions were revised in December 2025, and the only item flagged under What's New is that the fax numbers and mailing addresses moved to a different part of the instructions. No substantive rewrite. The traps are where they have been.

Four channels, one per day, and a tool that closes on Sunday morning

Do the state filing first. The IRS says it as an order of operations rather than as a rule: if you are creating a legal entity, register it with your state before you apply (IRS, Employer identification number, page last reviewed 17 July 2026), and the page behind the tool itself adds the consequence — if you do not form your entity with the state first, your EIN application may be delayed. The application asks for a legal name, and until the state has one on file you are guessing at it.

Then pick one channel and stay in it. The instructions put the warning in a single sentence: use only one method for each entity so you do not receive more than one EIN for an entity (Instructions for Form SS-4, Rev. December 2025, read 16 September 2026).

• Online, if your principal place of business is in the US or a US territory and you have the responsible party's SSN or ITIN. One session, no saving, and it expires after 15 minutes of inactivity. Availability is not what most people picture: Monday to Friday 6:00 a.m. to 1:00 a.m. the next day, Saturday 6:00 a.m. to 9:00 p.m., Sunday 6:00 p.m. to midnight, all Eastern time (IRS, Get an employer identification number, page last reviewed 19 August 2026). Late Tuesday night is fine. Sunday lunchtime is not.
• Fax Form SS-4 to 855-641-6935 from the 50 states or DC. Generally about 4 business days. Put a fax number on the form, because the IRS no longer sends back the SS-4 annotated with your number. It faxes a cover sheet carrying the EIN instead.
• Mail to Internal Revenue Service, Attn: EIN Operation, Cincinnati, OH 45999. About 4 weeks, and the instructions tell you to start 4 to 5 weeks ahead.
• Phone, and only if you are international. The IRS states flatly that it no longer issues EINs by telephone for domestic taxpayers. Applicants with no legal residence, principal place of business, or principal office in the US or its territories call 267-941-1099, Monday to Friday, 6:00 a.m. to 11:00 p.m. Eastern. Their fax numbers differ too: 855-215-1627 from inside the US, 304-707-9471 from outside, with mail going to the EIN International Operation at the same Cincinnati address.

Across all of them sits one hard cap. EIN issuance is limited to one per responsible party, per day, and the instructions specify that the limit applies to every request whether online, telephone, fax, or mail. If you are standing up two LLCs with the same person named on both, that is a two-day job no matter how you file.

Lines 1 and 2: the name is whatever the state's record says, minus the punctuation

Line 1 wants the legal name of the entity exactly as it appears on the charter or other applicable legal document. An entry is required. For an LLC that means the name on the filed articles or certificate of formation, including the suffix, character for character, and not the shortened version on your invoices.

Then the IRS system quietly narrows what a name is allowed to contain, and the rules for that are not in the instructions at all — they sit in a block headed Business Name & Address Rules on the EIN page. Its systems allow only letters A to Z, numbers 0 to 9, hyphens, and ampersands. The conversions are specific, and they are the sort of thing that produces a mismatch nobody notices for a year:

• Symbols such as plus signs, at signs and periods get spelled out or replaced with a space, so Jones.Com becomes Jones Dot Com or Jones Com.
• Slashes become a hyphen.
• Apostrophes are removed without adding a space, so a name like OBrien Design LLC is what the record ends up holding.

Street addresses get 35 characters. Use USPS abbreviations and put the suite number where it will survive the truncation rather than at the tail of a long line.

Line 2 is the trade name, meaning the doing-business-as name if it differs from line 1. The instructions attach a caution most people skip: use the full legal name from line 1 on all tax returns, and if you do put a trade name on line 2 and choose to use it, use that one consistently on every return. Mixing the two across filings is what generates the processing errors. Registering that name with a state or county office is a separate job from writing it on this line, and the office that takes it varies by state.

Lines 4a and 4b are the mailing address, and the instructions note that this address will generally be used on all tax returns. Lines 5a and 5b are the physical street address, filled in only if it differs, and never a PO box. Line 6 asks for the county and state of the entity's primary physical location, which is a question about where the business actually sits rather than where it was organized.

Lines 7a and 7b: a person, their own number, and no nominees

The responsible party is the person who ultimately owns or controls the entity or who exercises ultimate effective control over it. The IRS adds a practical test on top of that phrase: the person should have a level of control over, or entitlement to, the funds or assets in the entity that, as a practical matter, lets them control, manage, or direct the entity and the disposition of its funds and assets.

Three constraints on this pair of lines catch people out.

It has to be a natural person. The responsible party must be an individual, not an entity, and the only exception is for government entities, which may enter an EIN on line 7b. A manager-managed LLC whose manager is another LLC still names a human being here.

The number is theirs, not the company's. Line 7b takes an SSN or an ITIN. If the responsible party has neither and is ineligible to obtain either, the instructions say to enter foreign or N/A, and that an entry is required, so leaving it blank is its own rejection.

And a nominee cannot stand in. A nominee, in the IRS's own definition, is someone given limited authority to act for the entity during formation, with little or no control over its assets — which is exactly the arrangement a formation service sets up. The IRS is blunt about what that means here: nominees cannot apply for an EIN and should not be listed on Form SS-4, and if you used one to process the state formation you must identify the responsible party before you apply. Listing a nominee anyway could disclose your information to an unauthorized person, and the correction runs through Form 8822-B (IRS, Responsible parties and nominees, page last reviewed 22 August 2026).

Once the number exists, this is the line with an ongoing duty attached, and the instructions carry it as a standing note rather than as part of line 7: changes in responsible parties must be reported to the IRS within 60 days, on Form 8822-B. No new number, no fee, one page. That 60 is the form's figure rather than the regulation's, which matters more than it sounds and is worked through alongside the changes that do force a new EIN.

Lines 8a to 9a: the box that trips almost every LLC

This pair generates the most wrong filings, because the question people answer is not the question being asked.

Line 8a asks whether the application is for a limited liability company or a foreign equivalent. Line 8b takes the number of members. Line 8c asks whether the LLC was organized in the United States. If a single-member LLC is owned by an individual and their spouse in a community property state and they choose disregarded treatment, the instructions say to enter 1 on line 8b.

Line 9a then asks for type of entity, and the form carries a caution right on its face: if 8a is Yes, see the instructions for the correct box. There is no LLC box on line 9a, because line 9a is about federal tax classification, not about what you formed at the state office.

• Single-member LLC taking the default treatment: check Other and write disregarded entity in the space provided.
• Two or more members accepting the default: check Partnership.
• Filing Form 8832 to be taxed as a corporation, or Form 2553 to elect S corporation status: check Corporation and write the return number, 1120 or 1120-S.

The online assistant adds a rule the paper form never warns you about, and it is written down only in the manual behind the tool. Single and multi-member limited liability companies must select Limited Liability Company as the type of entity they are establishing, which allows an LLC suffix to be entered and the correct filing requirements to be set. Selecting Sole Proprietor or Partnership will not allow an LLC suffix to be added to the primary name line (IRM 21.7.13.3.4.1). A single-member owner who reasons that the LLC is disregarded, therefore Sole Proprietor is the honest answer, ends up with an EIN issued to a name that cannot carry LLC on it. The state record says one thing and the IRS record says another, and the first place that surfaces is a bank declining to open the account.

Nothing on lines 8 or 9 decides whether you need a new number if the LLC later changes shape. That is a separate question with a separate answer, and the regulation governing it points the opposite way from what most people expect.

Line 10 and its neighbours: the ones people answer like a survey

Line 10 is the reason for applying. Check only one box, do not enter N/A, and a selection is required.

The distinction that matters for an LLC is between Started new business and Changed type of organization. If you have been operating as a sole proprietor and have now formed an LLC, the second box is the accurate one, and the instructions ask you to specify the change in the space provided. Their own example is From sole proprietorship to partnership. That box is also where the trail of accounts that have to move out of your personal name properly begins.

Two other boxes are narrower than they sound. Banking purpose means you are requesting the number for banking purposes only, and you have to enter the purpose. Purchased going business comes with a caution: do not use the former owner's EIN unless you became the owner of a corporation by acquiring its stock.

Line 11, date business started or acquired, is the start date of the business. If you are changing the form of ownership, it is the date the new ownership entity began, which for an LLC is the effective date on the state's certificate rather than the day you first had the idea.

Line 12 is the closing month of the accounting year, meaning the last month of your accounting or tax year. On a calendar year, which is what an LLC ends up on unless someone deliberately put it somewhere else, that is December.

Line 13 asks for the highest number of employees expected in the next 12 months across agricultural, household, and other, entering zero if none. If you expect none, skip line 14 entirely.

Line 14 is the one with a lock on it. Checking it opts you into filing Form 944 annually instead of Form 941 each quarter, available if you expect employment tax liability of $1,000 or less in a full calendar year, which generally corresponds to $5,000 or less in total wages subject to Social Security, Medicare and withholding, or $6,536 or less for employers in a US territory. The caution underneath is the part to read twice: once you check the box, you must continue to file Form 944 regardless of the amount of tax shown on your return, until the IRS instructs you to file Form 941. It is not a preference you re-pick each January.

Line 15 is the first date wages or annuities were paid. If the business does not plan to have employees, enter N/A rather than leaving it blank.

Line 16 wants the principal activity, and you must check a box. The categories belong to the IRS, not to you, and the instructions define them in ways that do not always match how a business describes itself. Construction covers special trade contractors, plumbing through excavation. Real estate is for renting, leasing, managing, selling, buying or renting real estate for others, plus related services such as appraisal. Rental and leasing is tangible goods, autos through industrial machinery. Retail covers direct, mail-order and electronic sales, not only a fixed store. If none of them fits, check Other and specify. Line 17 then asks for more detail and an entry is required, with the instructions offering General contractor for residential buildings as the level of specificity they want.

Line 18 asks whether the entity on line 1 has ever applied for and received an EIN before, and if so, for the previous number.

The Third Party Designee block is optional and short-lived: it authorizes a named individual to receive the EIN and answer questions about the form, the signature area has to be completed for the authorization to be valid, and the designee's authority ends the moment the EIN is assigned and released. One operational quirk sits underneath it. If the designee's address or telephone number matches the taxpayer's, the application has to be mailed or faxed rather than filed online.

What the rejection code actually tells you

When an online application dies, you get three digits and no explanation, and there is no published list to look them up in. The Internal Revenue Manual section governing the online application tells assistors on the toll-free line that they must use the tables in paragraphs 8 and 9 to resolve every one of these calls — and in the public version of the manual those two paragraphs are not there. They appear as long rows of the triple-bar marks the IRS prints in place of official-use-only text. The same section states the position plainly for the people answering the phone: the online message does not provide a definition of the three-digit reference number.

What the manual does publish is the routing, and the routing is usable. Reference numbers 101 or 115 are directed to a customer service representative. Every other reference number is routed to an automated message which provides instructions to correct invalid information and resubmit the application or submit Form SS-4 by mail or fax. So the codes sort into two practical groups: one where a person has to look at your application, and one where the system is telling you a field was wrong and a retry is the intended response.

The manual also lists what the tool validates in real time, which narrows the likely causes considerably. It checks name and TIN match. It checks for an existing business name and EIN in the same state. And it runs other front-end checks. Only applicants who pass the validation receive an EIN during the session. A name collision inside your own state of formation is therefore a first-order suspect, and it is exactly the sort of thing that needs a human rather than an automated message.

One more screen looks similar and is not the same thing. If the system itself is down mid-application you are redirected to a Technical Difficulties page, which may also show a three-digit code at the bottom marked Internal Use Only. The guidance for that one is simply to try again later in the day or send the form by fax or mail. Same shape on screen, entirely different cause.

The confirmation notice is issued once

At the end of a successful session you get the option to view, save and print the CP 575. Take it, and understand the trade you are making: taxpayers who opt to receive their CP 575 online will not receive a notice in the mail. There is no second copy coming.

If it is already gone, what you can obtain later is a substitute rather than the original. Letter 147C, EIN Previously Assigned, comes from the business and specialty tax line. An entity transcript works for some purposes. Eligible Business Tax Account users can download a digital CP575, which the IRS says can be used as a substitute for the original notice series and for Letter 147C. Most banks and licensing offices accept the 147C, but it arrives when it arrives.

Timing after assignment is split, and that split is the source of a common panic. You can use the EIN immediately to open a bank account, apply for business licenses, and file a paper return. You have to wait up to two weeks before it will pass the IRS TIN Matching Program, before you can e-file a return, and before you can make deposits and pay electronically. A rejected e-file in week one is the system behaving as documented.

If a return comes due before the number does, the instructions give you the workaround: write Applied For and the date you applied in the space for the number, and do not substitute your SSN. If a deposit comes due first, the payment goes to the service center for your filing area with your name as shown on the SS-4, address, type of tax, period covered, and the date you applied.

One block on the IRS EIN pages is now narrower than it reads. Both the application page and the main EIN page still tell you that some corporations, limited liability companies and other entities may be required to report beneficial owners to FinCEN. That sentence remains true, but the set of entities it covers shrank sharply in August 2026, and an LLC formed in a US state is very likely outside it now. Read the FinCEN rule rather than the IRS summary of it before you put that filing on a calendar.

None of this is a tax question. It is a form-completion question, which is why the answers live in instructions and a procedural manual rather than in advice, and why the fix for a failed application is so often to fill in the same form again, on paper, and fax it.