To find your LLC number, start with the paperwork you already have: your state-issued formation document shows the state entity number, and the IRS CP 575 notice shows your federal Employer Identification Number (EIN). If those are gone, your state’s free online business entity search will return the entity number, and the IRS Business and Specialty Tax Line will confirm the EIN after verifying your identity.
Which route you take depends on which number you actually need. LLCs carry at least two: a state entity number assigned by the Secretary of State when the company was formed, and, in most cases, a federal EIN issued by the IRS.
Find Your State Entity Number on Formation Documents
The quickest source is the document filed to create the LLC. Depending on the state, it goes by Articles of Organization, Certificate of Formation, or Certificate of Organization. When the state approved the filing, it stamped or printed a unique number on the returned copy. Look near the top of the first page for a label such as “Filing Number,” “Entity ID,” or “Document Number.”
If you filed online, check your email for the approval confirmation or log back into the filing portal where you originally submitted the paperwork. Many states let you download a copy of the stamped document directly from your account.
Search Your State’s Business Database
If the formation paperwork is gone, nearly every state offers a free online business entity search through its Secretary of State or equivalent agency. These tools are open to the public and typically available around the clock. No login, no fee.
On the Secretary of State website, look for a link labeled “Business Entity Search,” “Corporate Database,” or something similar. Type the LLC’s exact legal name into the search field. The results show a profile for each matching registration, including the entity number, formation date, registered agent, and current standing. If the name is common, narrow the results by entity type or status.
These databases also keep records for dissolved or inactive companies. If your LLC is no longer active and you need the entity number for a final tax return or legal matter, filter for inactive entities or enter the name exactly as it appeared at formation.
State Entity Number Is Not the Same as a State Tax ID
A common mix-up: the state entity number and a state tax identification number are different things. The entity number is assigned by the Secretary of State and appears on formation documents, annual reports, and certificates of good standing. A state tax ID is issued separately by your state’s department of revenue when you register to collect sales tax, withhold employee income tax, or pay other state-level business taxes. Not every LLC has one. If you need to recover a state tax ID, contact the state’s revenue or taxation department directly; it will not appear in the Secretary of State database.
Find Your Federal EIN
The EIN is a nine-digit number the IRS assigns for federal tax reporting, in the format XX-XXXXXXX.1Office of the Law Revision Counsel. 26 USC 6109 Identifying Numbers Any entity other than an individual, including partnerships, corporations, and multi-member LLCs, must use an EIN on returns and statements.2eCFR. 26 CFR 301.6109-1 Identifying Numbers Before calling the IRS for a lost EIN, work through the records you probably already have.
Check the CP 575 Notice First
When the IRS approves an EIN application, it issues a CP 575 notice. If you applied online, a digital copy was available to download immediately; if you applied by mail or fax, the notice was mailed. This is the single most authoritative record of your EIN, so search email, filing cabinets, and cloud storage for it first.3Internal Revenue Service. Employer Identification Number
Other Documents That Show the EIN
If the CP 575 has disappeared, your EIN still shows up on several other records:
- Previous federal tax returns. The EIN is printed near the top of every Form 1065 (partnership return) or Form 1120-S (S corporation return) your LLC has filed.
- Bank account records. The bank that holds your business account collected the EIN when you opened it and can confirm the number.
- State and local license or permit applications. Many require the EIN, so copies of those filings may contain it.
- Prior IRS correspondence. Any notice or letter from the IRS about your LLC will reference the EIN.
The IRS itself recommends checking past tax returns, contacting your bank, and reviewing state or local license applications before calling.3Internal Revenue Service. Employer Identification Number
Call the IRS or Request a Transcript
If none of that turns up the number, confirm it directly with the IRS. You can request an entity transcript through the IRS’s online transcript service, which shows the EIN associated with your business. You can also call the IRS Business and Specialty Tax Line at 800-829-4933, open Monday through Friday, 7 a.m. to 7 p.m. local time (Alaska and Hawaii follow Pacific time).4Internal Revenue Service. Telephone Assistance Contacts for Business Customers
The IRS will verify your identity before sharing anything. Only a person authorized to act on behalf of the LLC, such as a member, a manager, or someone with a valid power of attorney, can receive the number. If you need written proof, ask the agent for Letter 147C, titled “EIN Previously Assigned.” This letter replaces the original CP 575 and is generally accepted by banks and state agencies as official EIN verification.3Internal Revenue Service. Employer Identification Number
When You Need an Official Document, Not Just the Number
The free state business search gives you the entity number at no cost, and Letter 147C gives you the EIN in writing. If instead you need a sealed, official version of your formation record, most states let you order a certified copy of the Articles of Organization or a Certificate of Status (sometimes called a Certificate of Good Standing) through an online ordering portal. Fees vary by state but generally run from $5 to $30 for standard processing, with expedited options costing more. Certified copies carry the state’s official seal and are accepted as proof of registration in court proceedings, bank applications, and government filings.