What is IRS Form SS4 and how do you use it to get an EIN?
by Team Devanta Authority
- December 23, 2025
- Bookkeeping & Tax
IRS Form SS4 is the official form used to request an Employer Identification Number, also known as an EIN. An EIN is a unique number issued by the Internal Revenue Service to identify a business entity for tax and reporting purposes. Most businesses need an EIN to hire employees, open a business bank account, file federal tax returns, or work with the IRS in an official capacity.
You use Form SS4 by providing basic information about your business, such as its legal name, entity type, responsible party, and the reason you are applying for an EIN. Once the form is submitted and approved, the IRS assigns an EIN to your business. In many cases, especially when applying online, the EIN can be issued immediately, while other submission methods may take longer to process.
What is Form SS4?
Form SS4 is an Internal Revenue Service form used to apply for an Employer Identification Number, or EIN. An EIN is a federal tax identification number assigned to a business or other legal entity so the IRS can track it for tax and reporting purposes.
Form SS4 collects basic details about the entity requesting the EIN, including the legal business name, entity structure, responsible party, and the reason for applying. Once the IRS processes the form, it issues an EIN that the business will use when filing federal taxes, communicating with the IRS, and completing many common administrative tasks.
What form is Form SS4?
Form SS4 is an IRS tax form used to apply for an Employer Identification Number, or EIN. It is a federal administrative form that allows the Internal Revenue Service to assign a unique tax identification number to a business, trust, estate, or other legal entity.
The form is not used to file taxes or report income. Instead, it is used solely to request an EIN so the entity can be properly identified when dealing with the IRS, filing federal tax returns, hiring employees, or opening financial accounts.
What does Form SS4 look like?
Form SS4 is a relatively short IRS form, typically one page long, laid out in a simple, numbered question format. It begins with basic identification fields at the top, such as the legal name of the entity, trade name if applicable, and mailing address. These fields are designed to clearly identify who is requesting the EIN.
The rest of the form consists of a series of clearly labeled questions that ask about the type of entity, the responsible party, the reason for applying, and basic business details such as when the business started and whether it will have employees. The layout is straightforward and text-based, with checkboxes and fill-in lines rather than complex schedules or calculations.
Why the IRS uses Form SS4 to issue EINs
The IRS uses Form SS4 to issue EINs because it provides a standardized way to collect the specific information needed to identify and classify an entity. By using a single, consistent form, the IRS can determine what type of organization is applying, who is legally responsible for it, and why an EIN is required.
Form SS4 also helps the IRS assign EINs accurately and avoid duplicate or incorrect records. The information on the form allows the IRS to link the EIN to the correct entity for tax filing, compliance, and communication purposes, ensuring that businesses and other organizations are properly identified throughout their lifecycle.
What information is needed on Form SS4?
Form SS4 requires basic but specific information that allows the IRS to correctly identify and classify the entity requesting an EIN. This includes the legal name of the business or organization, any trade name in use, and the mailing address where official IRS correspondence should be sent.
The form also asks for details about the type of entity, such as whether it is an LLC, corporation, partnership, trust, or another structure, along with the name and taxpayer identification number of the responsible party. In addition, you must indicate the reason for applying for an EIN, the date the business started or was acquired, and whether the entity expects to have employees or file certain federal tax returns.
Business name and responsible party
On Form SS4, the business name and responsible party are two of the most important pieces of information the IRS requires. The business name should be the legal name of the entity exactly as it appears on formation documents, such as articles of incorporation or organization, to ensure consistency across IRS records.
The responsible party is the individual who controls, manages, or directs the entity and its funds. This is usually an owner, partner, or principal officer, and the IRS requires their name and taxpayer identification number so there is a clearly identified person associated with the EIN for tax and compliance purposes.
Entity type and reason for applying
On Form SS4, the entity type tells the IRS how the organization is legally structured. This could be an LLC, corporation, partnership, sole proprietorship, trust, estate, or another recognized entity type. Selecting the correct entity type is important because it affects how the IRS classifies the business for tax filing and reporting purposes.
The reason for applying explains why the EIN is being requested in the first place. Common reasons include starting a new business, hiring employees, opening a business bank account, or meeting IRS filing requirements. This information helps the IRS understand how the EIN will be used and ensures it is issued and recorded correctly.
Foreign vs US applicants
Form SS4 can be used by both U.S. and foreign applicants, but the information required may differ slightly depending on the applicant’s status. U.S. applicants typically provide a Social Security Number or Individual Taxpayer Identification Number for the responsible party, which the IRS uses to verify identity.
Foreign applicants who do not have a U.S. tax identification number can still apply for an EIN using Form SS4. In these cases, the responsible party’s foreign identification information is provided instead, and the application may need to be submitted by mail or phone rather than online. The IRS uses this information to issue an EIN while recognizing that the entity and its owners may be based outside the United States.
How long does it take to get an EIN using Form SS4?
The time it takes to get an EIN using Form SS4 depends mainly on how the application is submitted. When Form SS4 is completed through the IRS online application system, the EIN is usually issued immediately after the information is validated.
If Form SS4 is submitted by fax or mail, processing takes longer. Fax applications typically take several business days, while mailed applications can take a few weeks to process. Delays may also occur if the information on the form is incomplete or requires additional review by the IRS.
How long does it take to process Form SS4?
Processing time for Form SS4 depends on the submission method and whether the information provided can be reviewed without follow-up. When Form SS4 is submitted online, the IRS processes it in real time and issues an EIN immediately in most cases.
When the form is submitted by fax, processing usually takes several business days. If Form SS4 is mailed to the IRS, processing can take a few weeks. Applications may take longer if there are errors, missing information, or if the IRS needs to verify details before issuing the EIN.
How fast can I get an EIN?
You can get an EIN as fast as the same day when applying online using Form SS4 through the IRS website. In most cases, the EIN is issued immediately after the application is completed and the information is successfully validated.
If you apply by fax, it usually takes several business days to receive an EIN. Applications submitted by mail take the longest and can take a few weeks to process. The fastest option is the online application, provided all required information on Form SS4 is accurate and complete.
What is the fastest way to apply for an EIN?
The fastest way to apply for an EIN is by submitting Form SS4 through the IRS online EIN application system. When the application is completed online during IRS operating hours, the EIN is typically issued immediately after the information is reviewed and accepted.
Other methods, such as applying by fax or mail, take longer because they require manual processing by the IRS. As long as the information on Form SS4 is accurate and complete, the online application remains the quickest and most efficient way to obtain an EIN.
EIN confirmation letters explained
EIN confirmation letters are official documents the IRS issues to confirm that an Employer Identification Number has been assigned to an entity. These letters serve as proof that the EIN exists and is associated with a specific business or organization, and they are often required by banks, payroll providers, and other institutions.
The most common EIN confirmation letter is issued when the EIN is first assigned, typically after submitting Form SS4. In some cases, the IRS may also issue a replacement or verification letter if the original document is lost or if the EIN needs to be confirmed later. These letters do not create a new EIN but simply verify the EIN already assigned to the entity.
What is the EIN confirmation letter?
The EIN confirmation letter is an official document issued by the IRS that confirms an Employer Identification Number has been assigned to a specific entity. It links the EIN to the legal name and address of the business or organization and serves as formal proof that the EIN is valid.
This letter is commonly required when opening a business bank account, setting up payroll, or verifying a business with third parties. It is issued after Form SS4 is processed and does not assign a new EIN; it simply confirms the EIN that has already been issued.
What is a CP575 / C575 document?
A CP575, sometimes referred to as a C575 document, is the original EIN confirmation letter issued by the IRS when an Employer Identification Number is first assigned. It is an official notice that confirms the EIN and links it to the legal name and address of the entity listed on Form SS4.
The CP575 is typically mailed to the address provided on the application and serves as primary proof of the EIN. If this document is lost, the IRS does not reissue a CP575, but it can provide a replacement verification letter, such as a Letter 147C, to confirm the existing EIN.
Why did I receive an IRS letter 147C?
You received an IRS Letter 147C because the IRS needed to confirm or verify your existing Employer Identification Number. This usually happens when a business requests EIN confirmation after losing the original EIN letter, when a bank or third party requires official verification, or when there is uncertainty about the EIN on record.
Letter 147C does not assign a new EIN. It simply confirms the EIN that has already been issued and links it to the correct legal name and address on file with the IRS. Businesses often request this letter when they cannot locate their original CP575 or need up-to-date EIN verification.
How long does it take to get letter 147C?
The time it takes to get IRS Letter 147C depends on how the request is made and how the IRS delivers the letter. When the letter is requested by phone and the IRS can verify the caller’s identity, it is often sent by fax the same day or within one business day.
If Letter 147C is sent by mail, it usually takes several business days to arrive, and in some cases up to a couple of weeks. The exact timing can vary based on IRS processing volume and whether any additional verification is required before the letter is issued.
How do I get a copy of my EIN letter?
To get a copy of your EIN letter, you need to contact the IRS and request official verification of your existing Employer Identification Number. If you no longer have the original EIN confirmation letter, such as the CP575, the IRS can issue a replacement verification letter instead.
The most common way to do this is by calling the IRS Business and Specialty Tax line and requesting a Letter 147C. Once your identity is verified, the IRS can send the letter by fax or mail. This letter serves as official proof of your EIN and can be used in place of the original confirmation letter for banks, payroll providers, and other third parties.
How can I get a copy of my EIN confirmation letter online?
You cannot download a copy of your EIN confirmation letter directly online through an IRS account or portal. The IRS does not provide a way to access or re-download EIN confirmation letters electronically after they have been issued.
If you need an official copy, you must contact the IRS and request EIN verification. In most cases, the IRS will issue a Letter 147C after verifying your identity. This letter can be sent by fax or by mail and serves as an official replacement for the original EIN confirmation letter, such as the CP575.
When you need to contact the IRS directly
You need to contact the IRS directly when your EIN cannot be verified or resolved through standard online processes. This often happens if you have lost your original EIN confirmation letter, if a bank or third party requires official EIN verification, or if there is a mismatch between the EIN and the legal business information on IRS records.
Direct contact with the IRS is also necessary when there are errors on Form SS4, delays that extend beyond normal processing times, or questions about the responsible party or entity classification. In these situations, speaking with the IRS allows issues to be clarified and resolved without creating a new EIN or submitting duplicate applications.
Common EIN & Form SS4 questions people ask the IRS
People commonly contact the IRS with general questions about EINs and Form SS4 when they are unsure how their business is identified or how their information is recorded. These questions often come up during business formation, banking, hiring, or when dealing with third parties that require official IRS documentation.
Typical questions include whether an EIN ever expires, whether a new EIN is needed after business changes, and how to verify or recover an existing EIN. Many people also ask about correcting mistakes on Form SS4, updating responsible party information, or confirming which IRS notices relate to EIN verification rather than new EIN issuance.
Is an EIN permanent?
Yes, an EIN is permanent once it has been issued by the IRS. It does not expire and remains associated with the entity for its entire existence, even if the business becomes inactive or stops operations for a period of time.
However, certain changes to a business, such as a change in ownership structure or legal entity type, may require applying for a new EIN. In those cases, the original EIN is not reused, but it also is not reassigned to another business.
How do I verify my identity with the IRS?
You verify your identity with the IRS by providing information that confirms you are authorized to act on behalf of the business or entity. This typically includes the legal name of the entity, the EIN, and personal identifying information for the responsible party, such as a Social Security Number or Individual Taxpayer Identification Number.
When contacting the IRS by phone, the representative will ask security questions based on the information on file to confirm your identity. In some cases, additional documentation or written authorization may be required. Identity verification is necessary before the IRS will discuss EIN details, issue verification letters, or make changes to business records.
What Form SS4 is not used for
Form SS4 is not used to file taxes, report income, or calculate tax liability. It does not replace federal tax returns, payroll filings, or any other IRS reporting forms. Its sole purpose is to request the assignment of an Employer Identification Number.
Form SS4 is also not used to register a business at the state level, obtain state tax IDs, or handle licenses and permits. In addition, it is not a tool for updating business information after an EIN has already been issued, such as changing an address or ownership details. Those actions require separate IRS procedures and forms, not Form SS4.
How to set up an LLC as a non-resident
IRS compliance
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Get a registered agent with a US address to receive IRS and state notices and stay compliant.
Form SS4 & EIN
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Obtain an EIN as a non-resident using Form SS4, even if you don’t have a Social Security Number.
After your EIN
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IRS filings
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Stay compliant with ongoing IRS filings and avoid penalties as your non-resident LLC grows.
Frequently Asked Questions about US LLCs for nonresidents
Starting and running a US LLC as a non-resident often raises practical and legal questions. Below you’ll find clear answers to the most common concerns around ownership, taxes, residency, and compliance, so you can move forward with confidence and avoid costly mistakes.
Form SS4 is an IRS form used to apply for an Employer Identification Number, or EIN. It allows the IRS to assign a unique federal tax identification number to a business or other legal entity.
Form SS4 requires basic details such as the legal name of the entity, entity type, responsible party, reason for applying, and business start date. This information helps the IRS correctly identify and classify the entity.
Processing time depends on how Form SS4 is submitted. Online applications are usually processed immediately, while fax submissions take several business days and mailed applications can take a few weeks.
An EIN can be issued the same day if you apply online through the IRS using Form SS4. Other application methods take longer due to manual processing.
The EIN confirmation letter is an official IRS document that confirms an EIN has been assigned to an entity. It is commonly required by banks, payroll providers, and other third parties.
IRS Letter 147C is sent to verify an existing EIN, usually when the original confirmation letter is lost or when official EIN verification is requested. It does not issue a new EIN.
To get a copy of your EIN letter, you must contact the IRS and request EIN verification. The IRS typically issues Letter 147C, which serves as official proof of your EIN.