Verifying a tax ID number confirms that a business is registered and that the number it gave you is real and active. This page shows you two things: how to verify a federal EIN with the IRS, and how to verify a state sales tax or reseller number using each state’s official verification tool. Every state link below points to an official government (.gov) source.
Need to apply for a number rather than verify one? You can start an EIN application here, or handle state-level business registration here.
How to Verify a Federal EIN with the IRS
An Employer Identification Number (EIN), also called a Federal Tax ID or FEIN, is a nine-digit number in the format XX-XXXXXXX issued by the IRS. It is worth knowing up front: the IRS does not offer a public tool to look up a business by its EIN. There is no searchable federal database where you can type in a number and see who it belongs to. EIN verification is instead done through official IRS confirmation documents or by contacting the IRS directly.
Confirming Your Own EIN
If you are verifying an EIN for your own business, the IRS recognizes these methods:
- EIN confirmation letter (CP 575) — the original computer-generated notice the IRS issues when your EIN is first assigned. Keep this document; it is the primary proof of your EIN.
- EIN Verification Letter (147C) — a replacement confirmation if the CP 575 is lost. It is accepted by banks, payroll providers, and licensing agencies. Request it by calling the IRS Business & Specialty Tax Line at 800-829-4933. The 147C cannot be requested online or by email; the IRS sends it by mail or fax.
- Business tax transcript (entity transcript) — available to authorized parties through the IRS and useful for confirming the EIN of record.
- Prior filings and records — past federal returns, bank account paperwork, and state or local license documents typically show the EIN you used.
Verifying Someone Else’s EIN
Because there is no public IRS lookup, confirming a third party’s EIN usually means asking them for their CP 575 or 147C letter, or using a limited public source where one applies:
- Nonprofit / tax-exempt organizations: use the IRS Tax Exempt Organization Search, which lets you look up exempt organizations and their EINs.
- Publicly traded companies: an EIN is often disclosed in filings on the SEC’s EDGAR system.
- Everyone else: request a copy of the IRS confirmation letter directly from the business.
Official IRS EIN Resources
- IRS — Employer Identification Number (overview & how to confirm an EIN)
- IRS — Get an Employer Identification Number (free online application)
- IRS — Get Transcript (business tax transcript)
- IRS — Tax Exempt Organization Search
The IRS provides EINs free of charge. You never have to pay a fee to obtain or confirm an EIN with the IRS.
How to Verify a State Sales Tax or Reseller Number
State verification is different from federal. Most states publish an online tool that lets you check whether a sales tax permit, seller’s permit, or resale/reseller number is registered and active — useful before you accept a resale certificate from a buyer or confirm a supplier is legitimate. A number of states have no public lookup; in those cases the accepted practice is to collect a properly completed state exemption/resale certificate and contact the department of revenue directly if you need confirmation.
Find your state below for the correct official verification link. If you still need to register, our business registration page can point you to the right filing.
State-by-State Tax Number Verification
Alabama
My Alabama Taxes (MAT) — choose “Verify an exemption certificate,” then enter the buyer’s ID (FEIN, ITIN, or SSN) and exempt sales account number.
Alaska
Alaska has no statewide sales tax and no state-level sales tax number to verify. Local sales taxes are administered by individual municipalities; where a local certificate applies, verify it with that municipality or the Alaska Remote Seller Sales Tax Commission.
Arizona
Arizona Department of Revenue — License Verification — enter the 8-digit Transaction Privilege Tax (TPT) license number.
Arkansas
Arkansas Taxpayer Access Point (ATAP) — under “Inquiries,” choose “Validate Sales Tax Permit,” then enter the permit ID.
California
California Department of Tax and Fee Administration (CDTFA) — under “How Do I…,” select “Verify a Permit, License or Account Now,” choose “Seller’s Permit,” and enter the identification number.
Colorado
Colorado Revenue Online — click “Verify a License or Exemption Certificate,” then enter the Colorado Account Number or Location ID (no hyphens or prefixes).
Connecticut
Connecticut License Lookup — choose “Lookup a License” and search by license number for a sales tax permit / resale certificate.
Delaware
Delaware has no statewide sales tax and issues no sales tax / resale number to verify. To confirm a business is registered, use the Delaware Division of Corporations entity search or the state’s business license lookup.
Florida
Florida Department of Revenue — Seller Certificate Verification — choose “Sales and Use Tax,” enter the contact name and the 13-digit certificate number, then verify. Phone verification: 877-357-3725.
Georgia
Georgia Tax Center — click “Verify Sales Tax ID(s),” accept the disclaimer, and enter the buyer’s sales tax number.
Hawaii
Hawaii Tax Online — Tax License Search — click “Search Tax Licenses” and enter the taxpayer name, DBA, or customer ID.
Idaho
Idaho State Tax Commission (TAP) — click “Validate a Permit,” choose “Sales & Use Tax,” and enter the 9-digit permit number (no hyphens).
Illinois
MyTax Illinois — choose “Verify a Sales Tax Exemption number (E-number)” and enter the customer’s exemption number.
Indiana
Indiana has no online resale certificate lookup. Obtain a completed Indiana General Sales Tax Exemption Certificate (Form ST-105) from the buyer, and contact the Indiana Department of Revenue with any questions.
Iowa
Iowa has no dedicated resale certificate lookup. As a workaround, use the state open-data Retail Sales & Use Business Registrations dataset to confirm the business is listed as “Active.”
Kansas
Kansas Department of Revenue — Exemption Certificate Verification — enter the buyer’s Kansas Tax Registration Number.
Kentucky
Kentucky has no online resale certificate lookup. Obtain a completed Kentucky Resale Certificate from the buyer and contact the Kentucky Department of Revenue with questions.
Louisiana
Louisiana Taxpayer Access Point (LaTAP) — use “Validate My Resale Certificate.” You must have a valid Louisiana registration and enter both your account and the buyer’s account details.
Maine
Maine Tax Portal — under “Additional Services,” choose “Sales and Service Provider Tax Resale and Exemption Lookup,” select “Resale Certificate,” and enter the certificate number and account ID.
Maryland
Maryland Tax Connect — Verify Sales and Use Tax Exemption — choose the exemption certificate number ID type and enter the buyer’s certificate number.
Massachusetts
MassTaxConnect — Sales Tax Resale Certificate Verification — choose “Sales Tax Account ID,” enter your seller account ID and the buyer’s account ID.
Michigan
Michigan does not issue exemption numbers and has no online lookup. Request the buyer’s FEIN or state business registration ID and contact the Michigan Department of Treasury to confirm.
Minnesota
Minnesota has no online resale certificate lookup. Obtain a completed Minnesota Certificate of Exemption (Form ST-3) from the buyer and contact the Minnesota Department of Revenue with questions.
Mississippi
Mississippi TAP — under “Tools,” choose “Verify a Permit Number,” select “Sales Permit,” and enter the buyer’s permit ID.
Missouri
Missouri has no resale certificate lookup. Obtain a completed Missouri Resale Certificate (Form 149). Missouri also publishes a list of businesses with revoked sales tax licenses; contact the Missouri Department of Revenue for confirmation.
Montana
Montana has no statewide sales tax and issues no sales tax / resale number to verify. To confirm a business exists, use the Montana Secretary of State business search.
Nebraska
Nebraska has no online resale certificate lookup. Obtain a completed Nebraska Resale or Exempt Sale Certificate (Form 13) and contact the Nebraska Department of Revenue with questions.
Nevada
My Nevada Tax — under “Registration and Licensing,” choose “Verify a License or Permit” and enter the buyer’s license or permit ID.
New Hampshire
New Hampshire has no statewide sales tax and issues no sales tax / resale number to verify. To confirm a business is registered, use the New Hampshire Secretary of State business search.
New Jersey
New Jersey On-Line Business Registration Certificate Service — enter the first four letters of the business name (“Name Control”) plus the business entity ID or certificate number.
New Mexico
New Mexico uses Non-Taxable Transaction Certificates (NTTCs). Verify certificates executed to your business by logging in to the New Mexico Taxpayer Access Point (TAP) and viewing the seller’s certificate options under your gross receipts tax account.
New York
New York Registered Sales Tax Vendor Lookup — complete the security check and enter the buyer’s sales tax identification number.
North Carolina
North Carolina Registry of Sales and Use Tax Numbers — enter the buyer’s Account ID / SST ID number and submit.
North Dakota
North Dakota Taxpayer Access Point — under “Lookups and Inquiries,” choose “Sales & Use Permit Inquiry” and enter the buyer’s permit number.
Ohio
Ohio Department of Taxation — Sales & Use Tax — download the “List of Active Vendors” spreadsheet and search it for the buyer’s sales tax ID number.
Oklahoma
Oklahoma Taxpayer Access Point (OkTAP) — under “Help,” choose “Search,” then “Sales Permits,” and enter the buyer’s permit or account ID.
Oregon
Oregon has no statewide sales tax and issues no sales tax / resale number to verify. To confirm a business is registered, use the Oregon Secretary of State business search.
Pennsylvania
Pennsylvania has no online resale certificate lookup. Obtain a completed Pennsylvania Exemption Certificate (REV-1220) from the buyer and contact the Pennsylvania Department of Revenue with questions.
Rhode Island
Rhode Island has no online resale certificate lookup. Obtain a completed Rhode Island Resale Certificate and contact the Rhode Island Division of Taxation with questions.
South Carolina
South Carolina has no online resale certificate lookup. Obtain a completed South Carolina Resale Certificate (Form ST-8A) and contact the South Carolina Department of Revenue with questions.
South Dakota
South Dakota has no online resale certificate lookup. Obtain a completed South Dakota exemption certificate and contact the South Dakota Department of Revenue via phone, chat, or email.
Tennessee
Tennessee TNTAP — under “Information and Inquiries,” choose “Sales & Use Tax Certificate Lookup,” select the certificate type, and enter the location ID or Streamlined Sales Tax ID.
Texas
Texas Comptroller — Sales Taxpayer Search — search by taxpayer ID, name, location, or ZIP; entering the buyer’s Taxpayer ID is most precise.
Utah
Utah has no online resale certificate lookup. Obtain a completed Utah Exemption Certificate (Form TC-721) and contact the Utah State Tax Commission with questions.
Vermont
Vermont has no online resale certificate lookup. Obtain a completed Vermont Resale Certificate (Form S-3) and contact the Vermont Department of Taxes with questions.
Virginia
Virginia has no online resale certificate lookup. Obtain a completed Virginia Resale Certificate (Form ST-10) and contact Virginia Tax with questions.
Washington
Washington State Department of Revenue — Business Lookup — choose “Reseller Permit Verification” to confirm a reseller permit is active.
Washington, D.C.
MyTax.DC.gov — under “More…,” choose “Search for Certificate/License Exemptions,” select “Resale Certificate,” and enter the account ID and certificate number.
West Virginia
West Virginia has no online resale certificate lookup. Obtain a completed Streamlined Sales Tax Certificate of Exemption and contact the West Virginia Tax Division with questions.
Wisconsin
Wisconsin My Tax Account — under “Businesses,” choose “Search account number/filing frequency,” select “Sales and Use Tax,” and enter the buyer’s ID, name, and ZIP.
Wyoming
Wyoming has no online resale certificate lookup. Obtain a completed Streamlined Sales Tax Certificate of Exemption and contact the Wyoming Department of Revenue with questions.
Frequently Asked Questions
Can I look up a business by its EIN on the IRS website?
No. The IRS does not publish a public tool to search a business by EIN. You confirm an EIN through the IRS confirmation letter (CP 575), an EIN Verification Letter (147C) obtained by calling the IRS, or a business tax transcript. Nonprofit EINs can be found through the IRS Tax Exempt Organization Search, and public companies often disclose an EIN in SEC filings.
How do I get an EIN Verification Letter (147C)?
Call the IRS Business & Specialty Tax Line at 800-829-4933 and request Letter 147C. It cannot be requested online or by email; the IRS delivers it by mail or fax. If you simply need to apply for a new EIN, you can begin an application here.
Why do some states have no online verification tool?
States that do not issue a lookup either have no statewide sales tax (such as Delaware, Montana, New Hampshire, and Oregon) or handle verification through a completed exemption/resale certificate and direct contact with the department of revenue rather than a public search. In those states, keep a properly completed certificate on file to support any tax-exempt sale.
Should I verify a resale or seller’s permit number before accepting it?
Yes. In most states the seller is held responsible if a tax-exempt sale turns out to be invalid. Verifying the buyer’s number against the official state tool — or keeping a complete, accurate certificate where no tool exists — protects you from having to repay uncollected tax plus penalties.
Where do I register if I don’t have a number yet?
If you need a federal number, you can start an EIN application here. For state sales tax, seller’s permit, or business registration, use our business registration page to get to the correct filing.
Online-Tax-Id-Number.org is a private third-party application assistance service. It is not a government agency and is not affiliated with or endorsed by any government agency. The official government links above are provided for your convenience. This page is general information, not legal or tax advice.