Guide
Tax ID Number Lookup (2026) Guide
Look up a Tax ID number using IRS tools, state databases, SEC EDGAR, or by requesting a W-9 form from the business. Different methods for different TIN types.
Methods
Tax ID Lookup Methods
| Method | Finds | Cost | |--------|-------|------| | IRS Tax Exempt Search | Nonprofit EINs | Free | | SEC EDGAR | Public company EINs | Free | | State SOS databases | Registered business EINs | Free | | W-9 request | Any business EIN | Free |
For EIN-specific lookup, see EIN lookup and EIN lookup by name.
Limitations
Why Tax ID Lookup Is Limited
Tax IDs are protected under IRC Section 6103. The IRS does not offer a public search for:
- Private company EINs
- Individual SSNs
- Individual ITINs
To find a private company's tax ID, request IRS Form W-9 directly from the company.
Frequently Asked Questions
Can I look up a tax ID online?
For nonprofits: yes (IRS search). For public companies: yes (SEC EDGAR). For private companies: no public tool.
How do I find a company's tax ID?
Request W-9 form from the company, search state SOS database, or use IRS nonprofit search for tax-exempt orgs.
Is there a free tax ID lookup?
IRS nonprofit search and SEC EDGAR are free. No free universal lookup for all businesses.
Can the IRS tell me someone's tax ID?
No. The IRS does not disclose others' tax IDs. You can only verify your own by calling 800-829-4933.
What if I lost my tax ID?
Call IRS at 800-829-4933 (EIN) or 800-829-1040 (ITIN). See lost EIN number guide.
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