How to Find Your Business Registration Number: The 3-Step Method

A business registration number is the unique identifier assigned by a government agency when your business entity registers with it, and in the United States it usually means one of four numbers: a state entity or file number from the Secretary of State, a state tax account number, a federal Employer Identification Number (EIN) or a local business license number. To find yours, follow 3 steps: identify which number the requester wants, check the document that agency issued, then use the agency’s official lookup tool or phone line.

There is no single national company registration number in the United States. Each agency issues its own, so a limited liability company (LLC) operating in two states can easily hold five or six different numbers. That is why a bank, a vendor portal and a city license renewal can all ask for a “business reg no” and mean different things.

This guide covers each number, where to locate it, how to obtain one, and what changes across states. Agency rules were reviewed November 2026; confirm details with the issuing agency.

What is a business registration number?

It is any official identifier a government agency gives your business when it registers, and the right one depends on the agency or form asking for it.

Whichever number applies, it is essential for dealing with tax authorities, banks and clients. The U.S. Small Business Administration (SBA) says you need an EIN to “pay federal taxes, hire employees, open a bank account, and apply for business licenses and permits” (SBA).

Washington’s Department of Revenue shows how loose the terminology is: it says its nine digit Unified Business Identifier (UBI) number “is sometimes called a tax registration number, a business registration number, or a business license number” (Washington Department of Revenue). In most other states, each number serves a separate agency.

The five numbers people most often mean:

State entity or file number

When you form an LLC, corporation or limited partnership, or register an out of state entity, the state filing office assigns an entity number. Names and formats vary. California’s entity number for a corporation “is a 7 digit number with a C at the beginning,” while a limited liability company or limited partnership number “is a 12 digit number with no letter at the beginning” (California Secretary of State). Florida uses a “6- or 12-digit number assigned by the Division of Corporations” called a document number (Florida Division of Corporations). Delaware calls it a file number, and New York calls it a DOS ID number, short for Department of State identification number (New York Department of State).

State tax account number

A state tax agency assigns its own account number when you register for sales tax, withholding or other state taxes. The SBA says the need for a state tax ID “ties directly to whether your business must pay state taxes” (SBA). Texas, for example, issues an “11 digit account number” called the Texas taxpayer number, separate from the Secretary of State file number (Texas Comptroller).

Employer Identification Number

The IRS describes an EIN as “a federal tax ID number for businesses, tax-exempt organizations and other entities” (IRS). For a deeper guide to federal and state tax numbers, see how to find your business tax ID number.

DBA filing number

If you operate under a trade name, the office that recorded it assigns a registration number. Florida’s fictitious name registration number “is 12 digits with the first digit being the letter ‘G'” (Florida Division of Corporations).

What is a business license number?

A business license number identifies a specific license or permit, not the business itself, and it is issued by the city, county or state agency that granted the license. It proves you are allowed to operate in a jurisdiction or carry on a regulated activity.

After registering, a Los Angeles business receives “a temporary Business Tax Registration Certificate or Registration Number,” and the permanent certificate is mailed within 4 to 6 weeks (Los Angeles Office of Finance). Texas issues a sales tax permit for “each active place of business,” with “the same taxpayer identification number but with separate outlet numbers” for each location (Texas Comptroller).

If someone asks “what is my business license number,” look at the license certificate posted at your location or the renewal notice from the issuing office.

Operating without a required registration has consequences. Washington tells new businesses, “Do not begin any business activity until you receive this license” (Washington Department of Revenue). In Florida, a business that fails to register its fictitious name cannot maintain a lawsuit in state court until it complies, and the failure is a noncriminal violation, although it does not void the business’s contracts (Florida Statutes 865.09). Our guide to how to look up, verify or get a copy of a business license covers license searches in more detail.

How do I find my business registration number? The 3-step method

The fastest way to find any of these numbers is to work in order: name the number, find the source document, then use the issuing agency’s tool.

Step 1: Identify which number you need

Read the exact field label and the form instructions. Clues usually point to one agency:

• “EIN,” “FEIN” or “federal tax ID” means your Employer Identification Number from the IRS.
• “Entity number,” “file number,” “document number,” “charter number” or “DOS ID” means your state entity number.
• “Taxpayer number,” “account ID,” “seller’s permit number” or “sales tax permit” means a state tax account.
• “License number” or “certificate number” usually means a city, county or state license.

For instance, banks usually want the EIN, and Secretary of State annual reports want the entity number. If the field is still unclear, ask the requester which agency issued the number they need. When searching, use the exact legal company name; Washington notes a tax account name “may not be the same as the trade name” or business name you use (Washington Department of Revenue).

Step 2: Check the documents that agency issued

Every number appears on various official documents and correspondence from the agency that assigned it. Start with your own records before searching online.

• State entity number: your filed articles of organization or incorporation, the filing confirmation, annual report notices and any certificate of status or good standing.
• State tax account number: the registration letter or permit from the state revenue agency, and the header of past returns. In Washington, new businesses receive “a letter from the Department of Revenue with your UBI/account ID number and filing frequency” (Washington Department of Revenue).
• EIN: the IRS notice issued when the number was assigned (the CP 575 series), the Letter 147C verification letter, past federal returns, and payroll forms.
• Local license number: the license or tax certificate posted at your location and renewal notices.
• DBA number: the confirmation letter. If the original certificate is lost, ask the issuing office for a new certificate or certified copy; Florida, for example, charges $30 for a certified copy of a fictitious name registration and $10 for a certificate of status (Florida Division of Corporations).

Step 3: Use the official lookup tool or contact the agency

If the paperwork is missing, go to the issuing agency. State entity numbers are public in most business search databases. Tax account numbers and EINs are confidential, so the agency will verify your identity before releasing them.

Where can I find my business registration number?

You can find your business registration number on the formation, tax or license documents the issuing agency sent you, or in that agency’s official business search database. For state entity numbers, the Secretary of State search tool is usually fastest.

Secretary of State business search tools

These official tools show entity numbers for registered businesses:

Details differ by state. Delaware says its free results include “the entity name, file number, incorporation/formation date, registered agent name, address, phone number and residency,” with certificates and copies available for a fee (Delaware Division of Corporations). Texas charges “a $1.00 statutorily authorized fee associated with each search” on SOSPortal (Texas Secretary of State). Florida lets you search by name, document number or FEI number (its term for the EIN) (Florida Division of Corporations).

State tax and license lookups

Some revenue agencies publish permit status. Washington’s Business Lookup can search “by tax account, reseller permit, and by general business license” (Washington Department of Revenue). Texas offers a Sales Taxpayer Search by taxpayer number, EIN, legal name or location, and a Taxable Entity Search for franchise tax status (Texas Comptroller). California’s Department of Tax and Fee Administration (CDTFA) offers a system to verify a seller’s permit, license or account, though not every account is disclosed (CDTFA). To retrieve your own account number, log in or create an online account with the applicable agency, or call its taxpayer line. Washington, for example, lets you add access to an existing license account with your UBI number and a Letter ID from a license-related letter (Washington Department of Revenue).

How do I find my EIN if I lost it?

You cannot look up an EIN in a public database. The IRS lists four places to check for a missing EIN (IRS):

• The notice the IRS issued when you applied
• The bank that holds your business account
• Agencies where you applied for state or local licenses
• Past business tax returns

If you still cannot find it, the IRS says to call 800-829-4933, Monday to Friday, 7 a.m. to 7 p.m. local time, and that it will “provide the number over the phone if you’re authorized to receive it” (IRS). Examples of an authorized person include a sole proprietor, a partner in a partnership and a corporate officer (IRS).

For written proof, request an entity transcript, call for Letter 147C (EIN Previously Assigned), or, as an eligible Business Tax Account user, download a digital CP575 that “can be used as a substitute for the original CP575A-J notice series and Letter 147C” (IRS). The original paper notice “cannot be duplicated or recreated,” but banks accept the digital CP575 as written confirmation of an EIN (IRS).

How to get a company registration number if you have none

If you have no number yet, register with the agency that issues it; what you need depends on your structure, location and activity.

• State entity number: file formation documents with your state’s business filing office. The SBA says an LLC, corporation, partnership or nonprofit corporation will “probably need to register with any state where you conduct business activities” (SBA).
• EIN: apply with the IRS. “You never have to pay a fee for an EIN,” and approved online applications receive the number “immediately,” though the IRS allows “only 1 EIN per responsible party per day” (IRS).
• State tax number: register with the state revenue agency before taxable activity starts. California requires a seller’s permit if you are selling taxable tangible personal property at retail, so you can collect sales tax (CDTFA). Texas charges no fee for a sales tax permit but may require a security bond (Texas Comptroller).
• Local license number: apply with the city or county where you operate.

Sole proprietors who have not formed an entity often have no state entity number at all. They may still hold a local license number, a DBA number or a state tax account, and the SBA notes banks typically ask for an EIN “or a Social Security number, if you’re a sole proprietorship” (SBA). LicenseComply does not form entities or give tax advice; an attorney or accountant can help with structure decisions.

What changes when you operate in several states?

A business operating in several states has a different state registration number in each one, while its EIN generally stays the same. As operations expand, tracking these numbers becomes a real compliance task.

• A new entity number in each state. The SBA says a business active in more than one state “might need to form your business in one state and then file for foreign qualification in other states,” by filing a Certificate of Authority (SBA). Each state then assigns its own number.
• A tax account in each state. Each state revenue agency issues its own account number, and Texas adds outlet numbers for each place of business under one taxpayer number (Texas Comptroller).
• Local license numbers at each location. Each city or county license carries its own number and renewal cycle.
• One EIN. The IRS says a corporation or LLC does not need a new EIN when it changes its name or location; a new EIN is generally tied to a change in ownership or structure (IRS).

Keep a register of every number, issuing agency, location and renewal date. Multi-state operators who want each location’s registrations and licenses checked and documented can use LicenseComply’s research and verification service. For the order to register in when expanding, see our guide on the registration sequence when opening in a new state.

Frequently asked questions

Is a business registration number the same as an EIN?

No. The difference is the issuing agency: an EIN is a nine digit federal tax number issued by the Internal Revenue Service, while a business registration number usually refers to a state entity number from the Secretary of State or another state or local identifier. Some forms use the term loosely. If the field says federal tax ID or EIN, use the EIN; if it says entity, file or document number, use the state number.

How do I find out my company registration number for free?

Check your formation documents, filing confirmation or annual report notice first, since the number appears on all of them. Many Secretary of State databases display entity numbers online; Delaware shows the file number free of charge. Some states charge a small fee, such as $1.00 per search on the Texas SOSPortal.

Do sole proprietors have a business registration number?

Often not a state entity number, because a sole proprietor does not file formation documents. A sole proprietor may still have a local license number, a DBA number, a state tax account or an EIN. Washington is an exception, assigning a Unified Business Identifier to sole proprietors who complete its Business License Application.

How long does it take to get a registration number?

It depends on the agency. The IRS issues an EIN immediately when an online application is approved. Los Angeles gives a temporary registration number after registration and mails the permanent certificate within 4 to 6 weeks. State filing offices set their own processing times for formation documents.

Can I look up another company’s registration number?

Yes, for state entity numbers. Secretary of State databases in California, Delaware, Florida, New York and Texas are public and show entity or file numbers for registered businesses. EINs are not publicly searchable. Texas and California let you verify a sales tax permit, which helps when accepting a resale certificate.

Official sources and further reading

• Internal Revenue Service: Employer identification number
• Internal Revenue Service: Employer ID numbers overview
• Internal Revenue Service: Get an employer identification number
• Internal Revenue Service: Lost or misplaced your EIN
• Internal Revenue Service: Understanding your CP575 notice
• Internal Revenue Service: When to get a new EIN
• U.S. Small Business Administration: Register your business
• U.S. Small Business Administration: Get federal and state tax ID numbers
• California Secretary of State: Business search field definitions
• California Secretary of State: bizfile Online business search
• California Department of Tax and Fee Administration: Online services and permit verification
• Delaware Division of Corporations: Entity search
• Florida Division of Corporations: Corporation records search guide
• Florida Division of Corporations: Fictitious name registration
• New York Department of State: Corporation and Business Entity Database
• Texas Secretary of State: SOSPortal
• Texas Comptroller: Sales tax permit FAQs
• Texas Comptroller: Comptroller databases
• Washington Department of Revenue: Business licensing and renewals FAQs
• Los Angeles Office of Finance: How to register for a Business Tax Registration Certificate
• Florida Statutes Section 865.09: Fictitious name registration
• Florida Division of Corporations: Fictitious name registration instructions and fees
• California Department of Tax and Fee Administration: Permits and licenses
• Washington Department of Revenue: Next steps for your new business
• Washington Department of Revenue: Apply online with My DOR

Sources last verified November 7, 2026. Requirements vary by jurisdiction; confirm current rules with the issuing agency.

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