Guide
Tax ID Number Lookup (2026) Guide
Look up a Tax ID number using IRS tools, SEC EDGAR, state databases, or a W-9 request. Different methods work for different TIN types. ein.so files Form SS-4 for non-residents from $49.
Look up a Tax ID number using IRS Tax Exempt Organization Search for nonprofits, SEC EDGAR for public companies, state Secretary of State databases, or a W-9 request for private companies. No universal public tax ID lookup tool exists. IRC Section 6103 protects most tax identification numbers as confidential federal information. You can verify your own EIN by calling the IRS at 800-829-4933. Non-residents who need a new EIN file Form SS-4; ein.so handles it for $49.
A Tax ID number, also called a Taxpayer Identification Number (TIN), is a 9-digit number the IRS uses to track a person or business for tax purposes. The three main types are the Employer Identification Number (EIN) for businesses, the Social Security Number (SSN) for individuals, and the Individual Taxpayer Identification Number (ITIN) for individuals without an SSN. Looking up a Tax ID depends entirely on which type you need and who it belongs to. Nonprofit and public company EINs are public records. Private company EINs, SSNs, and ITINs are confidential. This guide maps every legitimate lookup method, explains the legal limits, and shows non-residents how to obtain their own EIN.
| TIN Type | Issued To | Public Lookup? | Lookup Method |
|---|---|---|---|
| EIN (nonprofit) | Tax-exempt orgs | Yes | IRS Tax Exempt Search |
| EIN (public company) | SEC filers | Yes | SEC EDGAR |
| EIN (private company) | Private businesses | No | W-9 request |
| SSN | US individuals | No | Confidential |
| ITIN | Individuals (no SSN) | No | Confidential |
Methods
What Are the Methods to Look Up a Tax ID Number?
Four legitimate methods look up a Tax ID number: the IRS Tax Exempt Organization Search for nonprofits, SEC EDGAR for public companies, state Secretary of State databases for registered businesses, and a W-9 request for any private company. Each method targets a different TIN type and source.
No single tool returns every Tax ID. The IRS does not publish a master directory. You pick the method that matches the entity you are researching. The table below ranks each method by cost and what it returns.
| Method | Finds | Source | Cost |
|---|---|---|---|
| IRS Tax Exempt Search | Nonprofit EINs | irs.gov | Free |
| SEC EDGAR | Public company EINs | sec.gov | Free |
| State SOS database | Registered business records | State website | Free |
| W-9 request | Any business EIN | The company | Free |
| IRS phone (own EIN only) | Your own EIN | 800-829-4933 | Free |
For EIN-specific research, see EIN lookup and EIN lookup by name. To verify a number you already have, see EIN verification.
Nonprofits
How Do You Look Up a Nonprofit's Tax ID Number?
Look up a nonprofit's Tax ID number using the IRS Tax Exempt Organization Search at irs.gov, which returns the EIN, legal name, and tax-exempt status for free. Nonprofit EINs are public because tax-exempt organizations file disclosure returns the public can read.
The IRS tool searches registered 501(c)(3) and other tax-exempt entities. You enter the organization name, city, or state and the tool returns matching records. Two independent databases also publish this data from filed Form 990 returns.
IRS Tax Exempt Organization Search
ProPublica Nonprofit Explorer
GuideStar by Candid
The Form 990 Itself
Public Companies
How Do You Find a Public Company's Tax ID Number?
Find a public company's Tax ID number using SEC EDGAR at sec.gov, which is free. Public companies list their EIN on the cover page of SEC filings such as the 10-K annual report and the 10-Q quarterly report, labeled "IRS Employer Identification Number."
SEC-reporting companies must disclose their EIN in filings. Private companies and most foreign companies do not file with the SEC, so EDGAR will not have them. Follow these steps to find the number.
Open SEC EDGAR
Search the Company Name
Open a Recent 10-K or 10-Q
Read the EIN
EDGAR works only for SEC filers. For a private company, skip EDGAR and use the W-9 method described below.
Private Companies
How Do You Get a Private Company's Tax ID Number?
Get a private company's Tax ID number by requesting IRS Form W-9 directly from the company, which lists its EIN. No public IRS search returns private company EINs. The W-9 request is the standard business method when you must report payments on a 1099 form.
Private company EINs stay confidential under IRC Section 6103. The company itself is the source. Use one of these legitimate routes.
| Source | Where to Look | When It Works |
|---|---|---|
| Form W-9 | Request from the company | You pay the company and file 1099s |
| Past 1099-NEC / 1099-MISC | Your own records | The company already paid you or you paid them |
| Signed contract or invoice | Document header or signature block | The EIN was disclosed in writing |
| State SOS database | State business registry | The state publishes entity details |
| Business credit report | Dun & Bradstreet, paid services | You need due-diligence data |
A vendor or contractor must give you a completed W-9 when you request it for tax reporting. The form shows the legal name and the EIN on the same page. See EIN lookup IRS for what the IRS does and does not publish.
Your Own Number
How Do You Recover Your Own Tax ID Number?
Recover your own Tax ID number from your IRS CP 575 assignment letter, a prior business tax return, a bank application, or a payroll document. If none are available, call the IRS Business and Specialty Tax Line at 800-829-4933 to verify your own EIN after an identity check.
The IRS confirms your own EIN because you are authorized for that entity. It will not read out a number for a company you do not control. For an ITIN you cannot find, call 800-829-1040.
Check the CP 575 Letter
Check Prior Tax Filings
Check Bank and Payroll Records
Call the IRS
Why Limited
Why Is Tax ID Number Lookup So Limited?
Tax ID number lookup is limited because IRC Section 6103 classifies tax identification numbers as confidential federal tax information. The IRS publishes nonprofit and public company EINs only because those entities file public disclosure returns. Private EINs, SSNs, and ITINs are never published.
This privacy rule prevents identity theft and tax fraud. A leaked EIN can be used to open fraudulent accounts or file false returns. The same logic blocks public SSN and ITIN lookups entirely.
Tax IDs you cannot look up publicly
- Private company EINs are confidential. Request a W-9 instead.
- Individual SSNs have no public lookup. The Social Security Administration does not publish them.
- Individual ITINs are confidential. Only the holder and the IRS know them.
- You cannot use the IRS to find a third party's number. The agency confirms only your own.
Be cautious with third-party sites that promise a "universal tax ID lookup." Many sell repackaged public data or charge for information that government tools provide for free. See tax identification number for the full definition of each TIN type.
Non-Residents
How Do Non-Residents Get Their Own Tax ID Number?
Non-US residents get their own Tax ID number by filing IRS Form SS-4 by fax to 855-215-1627 to obtain an EIN. They enter their passport number on Line 7b. No SSN or ITIN is required. The IRS online EIN tool requires an SSN, so non-residents must use the fax method.
ein.so files this for you. The IRS charges $0 for the EIN. ein.so charges a service fee to prepare the SS-4, fax it, and deliver the assignment letter by email.
| Plan | Price | Processing Time | IRS Fee |
|---|---|---|---|
| Standard | $49 | 4-7 business days | $0 |
| Express | $97 | 2-3 business days | $0 |
What a non-resident needs for the SS-4
- A valid, unexpired passport (the passport number goes on Line 7b).
- Your US LLC or corporation name and formation state.
- Your foreign address for Line 4 (no US address required).
- The principal business activity for Line 16.
The IRS does not require you to visit the United States. See the full SS-4 form guide, the EIN without SSN guide, and EIN for non-residents for country-specific steps. To start now, apply for your EIN.
After the EIN
What Do You Do After You Get a Tax ID Number?
After you get a Tax ID number, you use the EIN to open a US business bank account, connect payment processors, file annual returns, and report beneficial ownership. The EIN is the federal identifier that links your business to the US tax and banking system.
A foreign-owned single-member US LLC has specific federal filing duties. Confirm your exact obligations with a US CPA, because ein.so does not provide tax advice.
Open a US Bank Account
File Form 5472 + 1120
File the BOI Report
Confirm the Cost and Timeline
If you need an ITIN as an individual rather than an EIN for a business, ein.so also files Form W-7. The ITIN service costs $197 Standard or $297 Express. See how to get an EIN for the complete process.
Next Steps
Find or Get Your Tax ID Number
- Look up a nonprofit or public EIN — use IRS Tax Exempt Search or SEC EDGAR, both free
- Get a private company EIN — request a W-9 or check the state EIN lookup by name
- Verify a number you have — see EIN verification or call 800-829-4933
- Get your own new EIN — non-residents file Form SS-4; see the SS-4 form guide
- Stay compliant — file Form 5472 and your BOI report on time
Related guides: EIN lookup | Tax identification number | EIN without SSN | EIN for non-residents | How to get an EIN | EIN cost
Frequently Asked Questions
Can I look up a tax ID number online for free?
Yes, for two categories. The IRS Tax Exempt Organization Search returns nonprofit EINs for free. SEC EDGAR returns public company EINs for free. No free tool returns private company EINs, individual SSNs, or individual ITINs. IRC Section 6103 protects those numbers as confidential federal tax information.
How do I find a private company's tax ID number?
Request IRS Form W-9 directly from the company, which lists its EIN. You can also search your state Secretary of State business database, check past invoices or 1099 forms, or read filed contracts. There is no public IRS search for private company EINs. The W-9 request is the standard method.
Can the IRS tell me someone else's tax ID number?
No. The IRS does not disclose another person's or company's tax ID. IRC Section 6103 makes tax identification numbers confidential. You can verify your own EIN by calling the IRS Business and Specialty Tax Line at 800-829-4933. The agent confirms numbers only after verifying you are authorized for that entity.
How do non-US residents get their own tax ID number?
Non-US residents get an EIN by filing IRS Form SS-4 by fax to 855-215-1627. They enter their passport number on Line 7b instead of an SSN or ITIN. The IRS online tool requires an SSN, so it is blocked for non-residents. ein.so files the SS-4 for $49 Standard or $97 Express.
What is the difference between an EIN, SSN, and ITIN?
An EIN is a 9-digit business tax ID issued by the IRS to companies. An SSN is a 9-digit personal number issued by the Social Security Administration to US citizens and authorized workers. An ITIN is a 9-digit personal tax ID for individuals who cannot get an SSN. All three are tax identification numbers.
What if I lost my own EIN?
Find your EIN on your IRS CP 575 assignment letter, a past business tax return, a prior bank application, or a payroll document. If those are unavailable, call the IRS at 800-829-4933 between 7am and 7pm local time. The agent verifies your identity and reads back your EIN. See the lost EIN guide.
Can I look up a nonprofit's EIN?
Yes. Use the IRS Tax Exempt Organization Search at irs.gov to find a registered nonprofit's EIN, name, and tax-exempt status for free. GuideStar and ProPublica Nonprofit Explorer also publish nonprofit EINs from filed Form 990 returns. Nonprofit EINs are public because tax-exempt organizations file disclosure returns.
How do I find a public company's EIN?
Search SEC EDGAR at sec.gov for free. Public company filings such as the 10-K annual report list the company EIN on the cover page under IRS Employer Identification Number. Enter the company name in EDGAR full-text search and open a recent filing. This method works only for SEC-reporting public companies.
Does ein.so look up existing tax ID numbers?
No. ein.so does not run a lookup service for existing tax IDs. ein.so files IRS Form SS-4 to obtain a new EIN for non-US residents who do not yet have one. Standard processing is $49 in 4-7 business days. Express is $97 in 2-3 business days. The IRS charges $0 for the EIN itself.
Is there a fee to look up a tax ID number?
The IRS nonprofit search, SEC EDGAR, and most state Secretary of State databases are free. Requesting a W-9 from a company is free. Some third-party data services charge for bulk EIN databases, but the official government tools cost $0. Obtaining your own new EIN from the IRS also costs $0.
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