Overview

A Taxpayer Identification Number (TIN) is the umbrella term the IRS and Social Security Administration (SSA) use to track taxpayers. An Employer Identification Number (EIN) is one specific TIN for businesses and certain entities.

If you need an EIN, it’s free. If you’re eligible, it’s issued immediately when you apply online via the IRS Apply for an EIN Online system.

Use TIN vs EIN as your quick mental model. TIN is the category. EIN is the business‑focused TIN.

What is a Taxpayer Identification Number (TIN)?

A TIN is any number used by the IRS or SSA to identify a taxpayer on tax returns, statements, and withholding documents.

You need a TIN when you file taxes, claim benefits, or receive reportable income. Payers also use it when they report payments to you.

The IRS summarizes the types and uses of TINs on its Taxpayer Identification Numbers (TIN) page. It also explains backup withholding if a correct TIN isn’t provided.

Decide which TIN you need by matching your role—individual, business, or tax professional—to the correct issuing agency and form. Then apply using the appropriate process.

Types of TINs: SSN, EIN, ITIN, ATIN, PTIN

The major TIN types cover both individuals and businesses. Each serves a distinct purpose and has its own issuing authority.

Start by identifying your role and which form you need (SS‑5 for SSN, SS‑4 for EIN, W‑7 for ITIN). Then apply with the correct agency using your exact legal name to prevent mismatches.

Who issues TINs and when they’re required

The SSA issues SSNs. The IRS issues EINs, ITINs, ATINs, and PTINs.

You must furnish a correct TIN on tax returns and on information returns, like Forms 1099. Payers typically obtain your TIN using Form W‑9.

If you fail to provide a correct TIN, certain payments may be subject to backup withholding. Both payers and payees may face penalties, as outlined in IRS guidance.

Use the right application channel for your situation. Ensure names and numbers match across all filings.

What is an Employer Identification Number (EIN)?

An EIN is a unique TIN for businesses and certain entities. It is used to file business, employment, and excise tax returns.

You also use an EIN to open business bank accounts, run payroll, and issue vendor tax forms. The IRS requires an EIN for entities like corporations and partnerships and for employers, plan administrators, and certain trusts and estates.

The fastest route is the IRS online application. It’s free and immediate for eligible applicants.

Determine whether your entity type or activities trigger an EIN requirement before opening bank accounts, hiring, or onboarding vendors.

When an EIN is required by the IRS

You must obtain an EIN in common cases such as the following. These are frequent triggers for EIN necessity.

If any of these apply, secure your EIN early. You’ll file on time, open accounts, and onboard vendors without delays.

Common business uses for an EIN

Even when not strictly required, an EIN enables smoother operations. You’ll use it to open bank accounts, apply for licenses, run payroll, and set up merchant accounts.

It also helps with payment processors and completing vendor and marketplace profiles. Because counterparties ask for a TIN on onboarding forms, using your EIN instead of your SSN can reduce exposure of personal information.

Obtain your EIN and use it consistently on tax and vendor documents. This keeps records aligned.

SSN vs EIN vs ITIN: the scenario-based decision guide

Choose between SSN, EIN, and ITIN based on your legal status and the form you’re completing. For U.S. individuals, an SSN is standard. For entities and employers, an EIN is required.

For non‑U.S. individuals without an SSN who still need to file or be reported, an ITIN applies. The Instructions for Form SS‑4 (EIN application) and the Instructions for Form W‑9 provide rules for entity classification and TIN selection.

Decide by entity type first. Then match your W‑9 classification and TIN to that entity.

Sole proprietors and single-member LLCs

Sole proprietors can use an SSN as their TIN for federal tax filings. Obtaining an EIN is recommended if you expect to hire, run payroll, or prefer not to share your SSN on W‑9s.

Single‑member LLCs (SMLLCs) that are disregarded entities generally use the owner’s SSN (or EIN) for income tax. An EIN may be required for payroll or excise taxes and is often preferred for banking and vendor forms.

On Form W‑9, a disregarded SMLLC typically checks “Individual/sole proprietor or single‑member LLC.” It provides the owner’s name and TIN unless the LLC has elected corporate tax treatment.

When uncertain, get an EIN for privacy and operational flexibility. Then follow the W‑9 instructions for disregarded entities.

Partnerships and corporations

Partnerships and corporations must use an EIN for tax filings and information reporting. SSNs or ITINs are not appropriate for entity tax returns.

These entities often issue and receive Forms 1099 and may run payroll. An EIN is necessary for both compliance and banking.

Ensure your W‑9 classification matches your entity type. Provide the entity’s legal name and EIN to avoid name/TIN mismatches.

Non‑US owners and entities

Non‑U.S. founders without an SSN or ITIN can still obtain an EIN. The IRS accommodates international applicants via fax or phone after submitting Form SS‑4.

The online system requires an SSN/ITIN for the responsible party. International applicants typically use the methods outlined in the Instructions for Form SS‑4.

Prepare formation documents and responsible party information before contacting the IRS.

State tax ID vs federal EIN vs local tax accounts

A federal EIN identifies your business to the IRS. State tax IDs and local accounts identify you to state workforce, withholding, corporate/franchise, and sales/use tax agencies.

You usually form the entity and obtain the federal EIN first. Then register for state payroll and sales tax accounts, and finally open any required local business tax accounts.

To find your state’s registration portal, use the Federation of Tax Administrators state agency list. Sequence your registrations so downstream accounts reference the correct legal name and EIN.

Which to get first and why

Start with your legal entity and EIN. State portals and banks rely on those identifiers and exact names.

Then register for state withholding and unemployment insurance if you run payroll. Register for sales tax if you have nexus or taxable sales.

Doing this in order prevents rejected registrations and payroll delays. Verify your entity legal name and EIN letter exactly match your formation documents before filing state applications.

Where to register for state payroll and sales tax

Each state runs its own portals for withholding, unemployment insurance, and sales/use tax registrations. Many states allow combined registrations.

Others require separate accounts. The Federation of Tax Administrators state agency list links to each state’s tax authority to start the process.

Make a checklist of required IDs for payroll and sales tax. Register in the states where you have employees, inventory, or taxable sales.

W-9, 1099, and backup withholding essentials

Using the correct TIN on Form W‑9 reduces reportable income errors and avoids backup withholding. Eligible payers can validate name/TIN combinations via the IRS TIN Matching Program.

When a payee refuses to provide a TIN or the TIN doesn’t match IRS records, payers may need to withhold at the backup rate on certain payments. Match your W‑9 classification to your legal entity and provide the TIN that corresponds to that classification.

Using the right TIN on Form W‑9

Form W‑9 collects your legal name, entity classification, and TIN so payers can report correctly on 1099s. Common pitfalls include listing an LLC’s name but providing the owner’s SSN without marking the correct “disregarded entity” line.

Using a “doing business as” name without the legal name also causes issues. The Instructions for Form W‑9 explain the correct name/TIN combination, especially for disregarded entities and grantor trusts.

Review the instructions before sending a W‑9. Verify that your legal name and TIN match IRS records to avoid mismatches.

TIN Matching, B‑Notices, and penalties

Authorized payers who file Forms 1099 can use the TIN Matching Program to validate a payee’s name/TIN before filing. If the IRS identifies a mismatch, it issues a “B‑Notice.”

The payer may need to begin or continue backup withholding until the payee provides a corrected TIN. Persistent errors can trigger penalties for incorrect information returns.

Proactive validation reduces risk and rework. Build a TIN validation step into vendor onboarding to prevent B‑Notices and withholding issues.

Privacy and identity theft considerations

Sole proprietors and SMLLC owners often use an EIN on W‑9s to avoid exposing their SSN. Many customers or platforms request a TIN.

Some counterparties—especially banks and payment processors—still need a responsible individual’s SSN for identity verification. Use your EIN widely for tax forms and vendor onboarding while recognizing that certain compliance processes still require personal identifiers.

Limit who sees your SSN and store tax IDs securely.

When using an EIN enhances privacy

Using your EIN is prudent when:

You’ll still use your SSN on personal returns. You may also need it to verify your identity with financial institutions.

Default to your EIN on W‑9s and standard business onboarding unless instructions specifically require your SSN.

Risk tradeoffs and exceptions

Banks and processors follow Know Your Customer (KYC) and Customer Identification Program (CIP) rules. They require the SSN (or equivalent) of beneficial owners or control persons, even when the business has an EIN.

Under FinCEN’s Customer Due Diligence (CDD) rule, institutions collect identifying information for individuals behind legal entities (FinCEN CDD Rule FAQs). Expect to provide both your EIN and personal identifiers during account opening.

Keep your EIN letter and government ID on hand to speed onboarding.

Multiple EINs, DBAs, and complex structures

You generally use one EIN per legal entity. Doing business under a different name (DBA) doesn’t require a new EIN.

Major events can require a new EIN. Examples include a change from sole proprietor to corporation or a partnership adding or removing partners.

The IRS publishes detailed rules on when a new EIN is required. Apply for a new number when your legal structure or ownership changes materially.

Keep your books organized so each EIN maps cleanly to one legal entity.

Subsidiaries, series LLCs, and divisions

Separate legal entities typically each need their own EIN for tax filing and banking. This includes subsidiaries, corporations under a parent, or distinct series within a series LLC where recognized by state law.

Internal divisions of a single legal entity don’t require separate EINs. Use location or department codes in your accounting system for clarity.

Align your legal structure with EIN assignments. Ensure information returns, payroll, and state registrations reflect the correct entity.

Avoiding duplicate or unnecessary EINs

Applying for multiple EINs for the same entity can cause reporting confusion and missed notices. Before applying, confirm whether a new entity was formed or whether a DBA will suffice.

If you accidentally created an extra EIN, work with your tax pro to consolidate activity under the correct number. Close the unused EIN to prevent future notices.

Applying for an EIN: methods, timelines, and costs

Getting an EIN is straightforward and free. For most U.S.-based applicants, the fastest path is the IRS online application.

It issues an EIN immediately after identity and data validation. Fax and mail are available when online isn’t an option, and international applicants can apply by phone.

Choose the channel that fits your situation and timeline. Ensure names and dates match your formation documents.

Online, fax, mail, and international phone

The online EIN Assistant provides instant issuance for eligible entities once you complete the application and pass validation. If you use fax, expect processing in days rather than hours.

Mail can take several weeks depending on IRS volume and time of year. International applicants who can’t use the online path typically submit Form SS‑4 and complete the process by phone per the Instructions for Form SS‑4.

Start online if you can. Otherwise, prepare a clean SS‑4 and use fax or the international phone process.

Costs and third‑party fee warnings

The EIN itself is free from the IRS. There’s no government fee.

Third‑party services sometimes charge to file on your behalf. They may add convenience but don’t accelerate government issuance.

Be cautious with sensitive data on unvetted sites. When in doubt, apply directly with the IRS to avoid delays and privacy risks.

Non‑US founders without an SSN or ITIN

Non‑U.S. founders can get an EIN without an SSN or ITIN by filing Form SS‑4. Use the IRS’s international application pathway.

The online system requires a U.S. TIN for the responsible party. International applicants should follow the fax/phone steps detailed in the Instructions for Form SS‑4.

Gather formation documents, a foreign address, and responsible party details before you apply. Follow the instructions precisely to reduce back‑and‑forth and processing delays.

Completing Form SS‑4 correctly

Focus on the basics that drive IRS validation. Use your legal entity name exactly as formed and include the responsible party’s full name.

Choose the correct entity type and reason for applying, such as “Started a new business” or “Banking purposes.” If the responsible party doesn’t have a U.S. TIN, the SS‑4 instructions explain how to proceed and which fields can be left blank.

Sign the form and use a mailing address that reliably receives IRS notices. If you’re unsure on any line, double‑check the instructions before submitting.

Common errors and how to avoid delays

The most frequent delays come from name or address mismatches and incorrect entity classification. Missing signatures and incomplete responsible party details also cause issues.

Inconsistent dates can trigger follow‑ups, such as formation date vs. first wages paid. Compare your SS‑4 against your formation documents and ensure responsible party information is complete.

If weeks pass without a response, call the IRS Business & Specialty Tax Line. Have your submission details ready to check status.

Post‑issuance maintenance: updating or closing an EIN

After you receive an EIN, keep it current with the IRS. If your responsible party or address changes, you must notify the IRS.

Businesses report a responsible party change within 60 days using About Form 8822‑B. If you shut down or no longer need the EIN, formally close the tax account so the IRS stops expecting returns.

Put reminders on your compliance calendar to file updates promptly.

Change responsible party or address

File Form 8822‑B within 60 days of a responsible party or business address change. This keeps IRS records accurate.

Late updates can cause misdelivered notices and penalties. The form is brief but must be signed by an authorized person.

Mail it to the address in the instructions and retain proof of mailing. Update state agencies and banks at the same time to keep records consistent.

Closing/canceling an EIN

To close your EIN, send a signed letter to the IRS with your legal name, EIN, address, and the reason for closure. Include your EIN assignment notice if available.

You must file any final returns due before the account is closed. Keep the closure confirmation in your permanent records and notify any states where you held tax registrations.

Verification and recovery: TIN Matching and EIN lookup

Payers can reduce filing errors by validating name/TIN combinations using the IRS TIN Matching Program. If you lose your EIN, it isn’t publicly searchable for privacy and fraud prevention.

Instead, check prior IRS notices, filed returns, or bank records. You can also call the IRS Business & Specialty Tax Line for assistance.

Keep a secure document vault for your EIN letter and W‑9. This speeds vendor onboarding and annual 1099 reporting.

Payer access to TIN Matching

To use TIN Matching, you must be an authorized payer who files Forms 1099. After registering with e‑Services, you can validate names and TINs before filing to avoid B‑Notices and backup withholding.

Make validation a standard vendor onboarding step. Re‑check before each filing season for high‑risk or high‑volume payees.

Lost EIN lookup and public lookup limits

There’s no open EIN directory for active businesses because it would invite fraud and identity theft. Retrieve a lost EIN by reviewing your CP 575 EIN assignment notice, prior tax returns, bank account records, or payroll filings.

You can also contact the IRS with identifying information. Limit which staff can view or share your EIN to reduce leakage.

Banking, payment processors, and KYC expectations

Even with an EIN, banks and payment processors may ask for a responsible individual’s SSN. This is part of KYC/CIP and beneficial ownership verification.

Financial institutions must identify and verify control persons and owners of legal entities under FinCEN’s CDD rule (FinCEN CDD Rule FAQs). Expect to provide your EIN, legal entity documents, and personal ID for onboarding.

Prepare both business and personal identifiers to speed account opening.

Why KYC still asks for SSNs

An EIN identifies your entity, but institutions must verify the people behind it for anti‑money‑laundering compliance. That’s why they collect SSNs (or foreign equivalents) of beneficial owners with a significant stake or control.

This is normal and not a substitute for providing your EIN on tax forms. Provide accurate ownership details up front to reduce back‑and‑forth.

Merchant accounts and marketplaces

Payment processors and marketplaces will ask for your EIN for payouts and tax reporting. They may still require SSNs for identity verification.

Verification can take from minutes to a few days depending on the provider. Name/TIN mismatches can extend the timeline.

Keep your W‑9, EIN letter, and legal documents handy to accelerate onboarding.

FAQs

Is a state tax ID the same as an EIN, and which do I need first?
No—an EIN is federal, while state tax IDs cover withholding, unemployment, and sales tax at the state level. Get your EIN first, then register with the state agencies where you have employees or taxable sales.

How long does it take to get an EIN online, by fax, or by mail in 2026?
Online issuance is immediate for eligible applicants. Fax typically takes days. Mail can take several weeks depending on IRS workload. If delayed, verify that your SS‑4 is complete and call the IRS Business & Specialty Tax Line.

Can a sole proprietor use an EIN instead of an SSN on Form W‑9 for privacy?
Yes. Sole proprietors can obtain a free EIN and use it on W‑9s to reduce SSN exposure. You’ll still use your SSN on personal returns. Ensure your W‑9 classification and name/TIN combination follow the instructions to avoid mismatches.

Do non‑US founders without an SSN or ITIN qualify for an EIN, and how do they apply?
Yes. International applicants can get an EIN by submitting Form SS‑4 and completing the IRS’s international phone/fax process per the instructions. The online tool requires an SSN/ITIN for the responsible party, so use the international pathway.

What’s the difference between FEIN, FTIN, and EIN, and which term should I use on forms?
FEIN (Federal EIN) and EIN are the same. FTIN (Foreign TIN) refers to a tax ID issued by another country. On U.S. tax forms, use “EIN” for your business’s federal ID and follow the form’s instructions.

How do I verify a contractor’s TIN and avoid backup withholding mistakes?
Register for the IRS TIN Matching Program if you file 1099s. Validate name/TIN combinations before payments and collect a complete W‑9. If the payee refuses a TIN or mismatches persist, backup withholding may apply.

When does a single‑member LLC need its own EIN versus using the owner’s SSN?
A disregarded SMLLC can use the owner’s SSN/EIN for income tax. It needs its own EIN for payroll or excise taxes, and many banks or vendors prefer an EIN. Check the W‑9 instructions for correct classification and TIN reporting.

Can one business have multiple EINs for different DBAs or divisions?
No—DBAs and internal divisions under one legal entity use the same EIN. Separate legal entities, such as subsidiaries or newly converted entities, generally require their own EINs. Avoid duplicate EINs to prevent reporting confusion.

How do I update the EIN responsible party or business name with the IRS?
File Form 8822‑B within 60 days for responsible party or address changes. Business name changes follow separate IRS procedures tied to return types. Update states and banks as well to keep records aligned.

Is there any cost to get an EIN, and are paid third‑party EIN services legit?
The EIN is free from the IRS. Paid services can file on your behalf but don’t accelerate processing. Apply directly unless you need hands‑on help.

Do I need an EIN to open a Stripe, PayPal, or bank business account, or will they still ask for my SSN?
Most providers accept an EIN for the business but still ask for a responsible individual’s SSN for KYC/CIP. This is standard under FinCEN’s CDD rule.

How do EINs interact with the new FinCEN beneficial ownership reporting rules?
EINs identify the entity, while beneficial ownership rules identify the people behind it. Expect parallel requests: EIN for tax reporting, and owner information for AML/KYC compliance.