Connecticut EIN Lookup
Last updated November 5, 2026 · Written by the EIN Registration filing team
Look up a Connecticut company
No EIN yet for your Connecticut business?
We file the SS-4 for you. EIN typically emailed in 2 to 4 business days (about 11 by fax).
Where to look in Connecticut
- Connecticut Business Records Search. Search by business name, business ALEI or filing number.
- Connecticut's business ID is the ALEI, which the state's open data expands as Authoritative Legal Entity Identifier. It is a state index, not a tax number.
Connecticut numbers that get mistaken for an EIN
None of these is the nine-digit federal number unless the table says so. A bank, payroll company or client asking for your EIN wants the one the IRS issued.
| Used for | Issued by | The number |
|---|---|---|
| Company formation | Connecticut Secretary of the State | business ID |
| State income tax withholding | Connecticut Department of Revenue Services | Connecticut Tax Registration Number, 7 or 8 digits plus a 3-digit location code |
| Unemployment insurance | Connecticut Department of Labor | Employer Account Number (EAN), 10 digits, written XX-XXXXX-X-XX |
| Sales tax | Connecticut Department of Revenue Services | Sales and use tax permit |
Finding your own Connecticut company’s EIN
Start with the CP 575 letter the IRS sent when the number was issued, then a past federal return, your bank’s account paperwork and your payroll provider. If none of those has it, the responsible party can call the IRS and ask for a 147C letter. Do not apply again to replace a lost number: a second application creates a second EIN for the same company.
Finding another Connecticut company’s EIN
If you pay them, ask for a Form W-9: it is the normal way to get the number, and you need it for a 1099 anyway. Nonprofits are in the IRS Tax Exempt Organization Search, and public companies print theirs on SEC filings. For a private Connecticut company with no reason to give it to you, there is no free public source that is complete. To check a number you were given, see how to verify an EIN.
Connecticut EIN lookup questions
Does Connecticut have an EIN lookup?
The EIN is federal, so the IRS issues it and Connecticut does not. The state describes a record as the business name, business ID, principal, agent, date formed, entity type and address, with no EIN among them.
Is my Connecticut business ID my EIN?
No. The business ID comes from the Connecticut Secretary of the State and identifies your company in state records. The EIN comes from the IRS, and a bank or payroll company asking for one will not accept the state number.
I formed my Connecticut company but never got an EIN. What now?
Forming the company does not create an EIN. You apply separately with the IRS on Form SS-4, or a service like ours prepares and files it for you. If you might already have one, check first: applying again gives the same company a second number.
Get Your EIN the Easy Way
Answer a few questions in about 5 minutes. Our specialists prepare your IRS Form SS-4, file it, personally handle any rejection or name conflict along the way, and get your EIN to you, typically within 2 to 4 business days, or about 11 when the IRS requires the application by fax. One flat $197 service fee. No upsells, no subscriptions.
- ✓ Prepared and filed by specialists
- ✓ Error 101 and rejection handling included
- ✓ Data encrypted (AES-256)
- ✓ Order tracking and email updates
Related guides
Sources
You can also apply for an EIN directly with the IRS at irs.gov at no cost.