What Is a Business Reg Number?
In the U.S., a business registration number is a unique ID given to your business by the government when you register, pay taxes, or get licenses. It acts like your business’s ID card and is needed for things like filing taxes, opening bank accounts, applying for permits, or answering government requests.
Unlike some other countries that use a single company registration number for all entities, the U.S. uses multiple types of registration numbers—such as the Employer Identification Number (EIN), state registration numbers, or entity numbers—depending on the type of registration and the issuing agency. In practice, when someone asks for your “business reg no” or “registration number company,” they may be referring to any of these distinct identifiers, which is why understanding which number is needed in context is critical.
Key Takeaways
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A business reg number is any official ID a government agency assigns to your business when you register, pay taxes, or obtain licenses, and you often need it for banking, taxes, permits, and contracts.
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In the U.S., “business registration number” is an umbrella term that can mean a state entity or company registration number, an EIN (federal tax ID), a state tax ID, or a license/permit number, depending on context.
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An EIN and a state company registration number are different: the EIN is a federal tax ID from the IRS, while the company registration number comes from your state’s corporate filing office and is tied to legal formation and state filings.
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You usually find your business reg numbers on official documents (formation papers, registration certificates, tax letters, past returns) or through state business search tools and state/IRS contact channels if documents are missing.
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LLCs, corporations, nonprofits, and partnerships typically have both a state entity number and an EIN, while sole proprietors may rely on a local license number or their SSN/EIN, depending on the form’s instructions.
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A business registration number is different from a business license number: registration numbers identify the business itself, while license numbers identify specific permissions or activities (like running a restaurant or contracting).**
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Keeping track of all your registration numbers helps you stay in good standing, avoid penalties, and quickly verify or prove your status to banks, vendors, regulators, and licensing authorities.
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LicenseComply assists by identifying which registrations and numbers you need, handling filings you authorize, and supporting renewals and updates for the licenses you engage them to manage, especially as you expand into new locations.
The Main Types of Business Registration Numbers in the U.S.
To figure out which number you need, start by learning about the most common business registration numbers in the U.S. The term “business registration number” can mean different things, including state entity IDs and numbers like the EIN for tax purposes.
Is a Business Registration Number the Same as an EIN?
Many people mix up a business registration number with an EIN. These are not always the same and are usually different.
- The Employer Identification Number is a federal tax ID issued by the IRS for tax reporting and payroll.
- The company registration number or state entity number is issued when you form an LLC, corporation, or similar entity with the state.
These numbers are different and should not be swapped on official forms.
Why Your Business Reg Number Matters
Your business registration number is important for following the law, filing taxes, and running your business. You’ll need it for:
- Filing federal, state, and sometimes local tax returns and reports
- Opening business bank accounts and merchant accounts, where lenders and payment processors use the number to verify your status
- Applying for state and local business licenses, permits, and registrations
- Completing vendor onboarding and contract forms when customers need to verify that you are a registered entity
- Looking up your entity record or confirming good standing in state online databases
Registration numbers let authorities check if your business is up to date with filings and payments. Keeping track of these numbers helps you avoid fines, losing good standing, or having your license taken away.
The 3-Step Method: How to Find Your Business Reg Number
Because “business reg number” can mean different things depending on who’s asking, follow these three steps to find the right one quickly.
Step 1: Identify Which Number You Actually Need
Before you start searching, clarify the type of registration number the requesting party needs. Look for clues in:
- The form or portal you are completing (e.g., “state registration number,” “EIN,” “tax identification number,” “entity ID,” or “certificate number”)
- The context of the request: Bank applications or payroll providers usually need an EIN, sometimes plus the state entity number. State annual reports, business license renewals, or Articles amendments require the state entity or company registration number. Sales tax permits or state employer registrations call for a state tax ID or employer account number.
For any “business registration number lookup” in the U.S., you’ll typically need to determine whether you’re dealing with a corporate registry (state database) or a tax authority (IRS or state revenue department) before searching.
Step 2: Check Your Official Business Registration Documents
After you know which number you need, the quickest way to find it is by checking your own documents.
For a state company registration number or entity ID:
- Check your Articles of Organization (LLC) or Articles of Incorporation (corporation) from your Secretary of State or similar office. These usually list the entity number in the heading or margin.
- Review any registration approval letter or email sent after you registered your new business online.
For your EIN (federal tax identification number):
- The IRS CP 575 EIN confirmation letter is sent when the EIN was first issued
- Prior federal tax returns: look at Form 1120 for corporations, Form 1065 for partnerships, or Schedule C attachments for single-member LLCs filing with a personal return. The EIN appears in the header of these documents.
- Payroll tax filings and W-2/W-3 transmittals, which also list the EIN
For state tax or employer numbers:
- State tax registration letters (sales and use tax, withholding, and unemployment) sent by the state revenue or labor agency
- State business registration certificate or tax account notice assigning an account or registration ID
Most business owners can find their registration number by checking these documents before looking it up elsewhere.
Step 3: Use Official Online Databases or Contact Agencies
If you can’t find the number in your paperwork, try using official government search tools or contact the agency that issued it.
For state business registration numbers (company/entity numbers):
- Go to your state’s Secretary of State (SOS) website or equivalent business registry (e.g., Department of State, Division of Corporations).
- Use the business search tool to perform a business number lookup by your legal name or assumed name.
- Once you locate your entity record, the registration number or entity ID is typically displayed near the top, along with status and filing details.
States like California and Washington have online databases where you can search for your business’s name, status, and registration number. You can print or download these records.
For an EIN:
The IRS does not let you search for a company’s EIN by name online. If you lose your EIN, check your confirmation letter or past tax returns first. If you still can’t find it, call the IRS Business & Specialty Tax Line. They will verify your identity and give you the number if you are allowed to get it.
For state tax IDs and employer numbers:
- Visit your state’s revenue department or employment department website and log in to your business’s online account, where your registration numbers are typically shown.
- If you can’t get online, call the agency’s business help line. After they confirm your identity, you can ask for your number.
Where Can I Find My Business Registration Number? (Common Scenarios)
Different types of businesses in the U.S. commonly register in specific locations.
LLCs and Corporations
For LLCs and corporations, the main registration number is usually the state entity or company number you get when you form the business. You can usually find it:
- On your Articles of Organization or Articles of Incorporation, as filed with the state
- On your business registration certificate or certificate of good standing obtained from the state
- In your online record on the state’s business search database, under fields like “Entity ID,” “File Number,” or “Registration Number.”
These businesses also usually have an EIN if they have employees, more than one owner, or are taxed as a corporation. The EIN is their federal business ID.
Sole Proprietors and Single-Member LLCs Without a Separate EIN
Many sole proprietors and some single-member LLCs use the owner’s Social Security Number for federal taxes at first. If they haven’t set up an LLC or corporation, there may not be a state entity registration number. Still, a local business license, assumed name certificate, or state tax permit can create a local or state registration number.
If a form asks for a “business ID number” or “business registration number,” these owners may need to use their EIN if they have one. If not, and if the instructions say it’s okay, they might use their SSN.
Nonprofits, Partnerships, and Professional Entities
Nonprofits, partnerships, and professional corporations or LLCs also receive state entity numbers when they register and obtain EINs for tax reporting. They will usually locate their business registration numbers:
- In the approved Articles or organization documents from the state
- On correspondence from the state charity or professional licensing board, if applicable
- In state business search databases that maintain public records
Business Registration Number vs. Other Identifiers
Since “business reg number” can mean different things, it’s important to know the differences. Each number has its own use and is handled by different agencies, so using the right one is key for staying compliant.
Business Registration Number vs. Company Registration Number
In many jurisdictions, “company registration number” is simply another name for the state-issued entity or registration number assigned when your business is formed. The company registration number is one of the principal forms of business registration, alongside EINs.
Business Registration Number vs. EIN (Federal Tax ID)
An EIN is a federal tax identification number, while a company registration number is tied to state-level legal formation:
- EIN: Issued by IRS; used to file federal taxes, manage payroll, and interact with financial institutions.
- Company registration number: Issued by a state corporate registry; used to file state annual or biennial reports, prove existence, and obtain certain state or local licenses.
These numbers work together. One proves your business exists at the state level, and the other is for federal taxes.
Business Registration Number vs. Business License Number
A business license number is tied to a specific license or permit, not to the business itself. For example, a city business license lets you operate in that city, and a health permit number allows you to run a restaurant or food truck. A license number shows you have approval for certain activities, but the business registration number is your main ID for legal and tax purposes.
State Business Registration: How It Ties Into Your Business Reg Number
“State business registration” in the U.S. usually refers to filing formation or registration documents with a state agency (often the Secretary of State), which, in turn, generates the company’s registration number or entity ID.
Key points about state registration numbers:
- They are assigned when your organization’s documents are accepted and recorded in the state’s system.
- They remain associated with your company throughout its existence in that state and appear in public records.
- Many states require you to reference this number when filing annual reports, amendments, or dissolution documents.
When you register a business online, the confirmation you get will usually show an entity ID. This acts as your state business registration number.
Registering a New Business Online and Getting Your Number
For new businesses, signing up online is usually the quickest way to get a business registration number.
Typical Online Registration Path
While each state differs, a common pattern for online business registration is:
- Create an online account on the Secretary of State or business registration portal.
- Choose your entity type (LLC, corporation, nonprofit, etc.).
- Complete and file the formation document electronically.
- Pay the required state filing fee.
- Receive a confirmation page or email with your entity’s official details, including the registration or file number.
This confirmation often serves as your first business registration certificate or proof, and it’s where your new company registration number first appears.
Obtaining an EIN After Registration
After your business is registered with the state, many owners apply for an EIN using the IRS website, by mail, or by fax. The EIN letter gives you your federal business ID, which goes along with your state registration number. You’ll need both for things like opening bank accounts, setting up payroll, and applying for licenses.
Business Registration Certificate and Documents: Why You Should Keep Them
Your business registration certificate and related documents are the primary evidence of your business registration numbers. These documents generally include:
- The official name of your business
- The date of formation or registration
- The state or local jurisdiction of registration
- Your registration or file number and sometimes additional statement IDs
Keep copies of these certificates and your EIN letter in a safe but easy-to-find place. Having them ready makes things like license applications and lender checks much easier.
Business Number Lookup: When You Need to Verify or Research a Business
“Business number lookup” tools in the U.S. are primarily provided by state corporate registries and certain industry-specific regulators. You can use these tools to:
- Verify that a vendor or partner is properly registered and in good standing
- Confirm the exact legal name, entity type, and registration number for contract drafting or compliance checks
- Check whether your own entity is active, dissolved, or delinquent and see the filing history
Since EINs are not usually searchable in public databases, business number lookups in the U.S. mostly focus on state entity numbers and sometimes license numbers, but not EINs.
How LicenseComply Helps
LicenseComply helps make business registration numbers easier to handle. You get expert advice on what you need and hands-on help with filing for the licenses and registrations you want us to manage.
Here’s what that looks like:
- Clarity on what you really need
We begin by researching and assessing the licenses you need for each location. This way, you know exactly which IDs and licenses apply, like state entity numbers, EINs, state tax accounts, and industry-specific licenses. - Done‑for‑you filings, from start to approval
After you approve the plan, our team prepares and files the applications, works with the agencies, and helps you go from “not started” to “approved” without drowning in paperwork. - Ongoing help, only where you want it
For licenses and registrations you sign up for ongoing service, we can take care of renewals, name or address changes, and closures. This keeps those tasks off your to-do list while you stay in control of costs and what we handle. - Built to scale with multi‑location businesses
If you’re opening in a new city or state, we can handle research and filings for each new location. This helps you get the right numbers and licenses every time you grow.
Contact us to talk through your locations, industry, and goals, and we’ll outline exactly how LicenseComply can help with your business registration numbers.
FAQs: Business Registration Numbers
Is a business registration number the same as an EIN?
No. An EIN is a federal tax ID issued by the IRS, while a business registration number often refers to a state-issued entity or company number. Some forms use “business registration number” as a catch‑all term, so always check whether they’re asking for your EIN, state entity ID, or another number.
How do I know which business registration number a form is asking for?
Look at the exact field label and any instructions on the form. If it mentions “EIN” or “federal tax ID,” use your EIN. If it mentions “entity ID,” “state registration number,” or “file number,” it usually means your state company registration number. If it references “account number” or “tax registration,” it may mean a state tax ID.
Where can I find my business registration number?
Start with your own documents: Articles of Organization/Incorporation, registration certificates, state tax registration letters, and your IRS EIN confirmation letter or past tax returns. If you still can’t find it, use your state’s business search website or contact the relevant agency (state filing office, tax department, or IRS).
Do sole proprietors have a business registration number?
Not always. If you have not formed an LLC or corporation, you may not have a state entity number, but you may still have IDs from local business licenses or state tax registrations. Some forms will let a sole proprietor use an EIN (if they have one) or, in certain cases, a Social Security Number if the instructions say that’s allowed.
How can LicenseComply help me with my business registration numbers?
LicenseComply can research which registrations and IDs you need, then prepare and file the applications you approve for your locations and activities. For licenses you specifically engage us to manage, we can also assist with renewals and updates. Contact us to discuss your situation and get guidance tailored to your business.
Disclaimer: This article is for information only and is not legal, tax, or accounting advice. We’ve made a reasonable effort to keep the content accurate and up to date, but laws and regulations change, and how they apply can vary based on your specific situation. You should consult with a qualified attorney, tax professional, or other licensed advisor before making decisions or taking action based on this information.