Business structure basics
When a sole proprietorship is enough, when an LLC and an EIN are worth the paperwork, what a DBA actually is, and what each one costs in your state.
↳Not legal or tax advice. Use this to prepare your questions, then confirm current rules with your Secretary of State and the IRS.
4Structures
7Questions
3Filing flows
StateRules vary
Starting a side business raises the same question for almost everyone: do I need an LLC? The honest answer depends on what you do, who you meet, and what you could lose. Many side businesses run legally for years as sole proprietorships with nothing filed at all. Others carry real liability risk, a partner, or meaningful revenue that make an LLC worth its fees. In between sit two simple tools, an EIN and a DBA, that solve banking and branding without a new entity. Costs vary sharply by state, so the same choice can be cheap in one place and expensive in another. This guide explains each option in plain language, then helps you match one to your case. Seven quick questions produce a suggested setup and the filing steps behind it. Nothing you enter leaves your browser. Treat the result as preparation for official sources, not legal advice.
The moment you earn self-employment income, you already have a legal structure. That default is a sole proprietorship, which requires no filing and reports income on Schedule C of your tax return. Its main drawback is personal liability, since you and the business are legally the same person. An LLC changes that by creating a separate entity that can shield personal assets when it is run properly. It does not make a business more legitimate or lower taxes for most single-owner ventures. Structure should follow your real activities, revenue, and risk rather than what sounds professional. State rules add a third layer, because fees and annual taxes differ widely across the country. These three principles shape every recommendation in this guide. Keep them in mind before paying any formation service. They prevent most expensive mistakes.
Read these before you file anything
First.
Structure follows what you actually do.
Pick a structure based on your real activities, revenue, and risk, not on what sounds professional. The right one protects you without paying for paperwork you do not need.
Second.
An LLC buys liability protection, nothing else.
It does not make a business more legitimate or cut taxes for most single-owner side businesses. It separates business assets from personal ones.
Third.
State rules vary, a lot.
The federal EIN is the same everywhere. Formation fees, annual fees, franchise tax, DBA rules, and publication requirements change sharply by state.
Most side businesses deal with some mix of four legal tools. The sole proprietorship is the automatic default and costs nothing to start. A DBA, short for doing business as, lets you operate and bank under a brand name, but it creates no entity and no protection. An EIN is a free federal tax identification number from the IRS. You can apply for an EIN online in about ten minutes, and you should never pay a service to do it. An LLC is a state-registered company that separates business debts from personal assets if you keep finances apart. It brings a formation fee, often an annual report, and in some states a yearly tax. You may need one of these tools, several, or none beyond the default. The cards below compare cost, time, protection, and typical fit side by side. Read them once before answering the case questions.
Compare them side by side
Sole proprietorship
DefaultThe structure you already have once you earn self-employment income. Nothing to file, and income goes on Schedule C. The trade-off is personal liability for business debts and claims.
Cost$0 to start
TimeAutomatic
ProtectionNone
Best forLow-risk work, testing an idea
DBA (trade name)
OptionalA state or county registration that lets you operate under a name other than your own. It is not a legal entity and offers no protection, but it helps you bank and market under a brand.
CostAbout $10 to $100
Time1 to 4 weeks
ProtectionNone
Best forSole props who want a brand
EIN (federal tax ID)
Federal · freeA free federal tax ID from the IRS, issued online in minutes. Required for an LLC with a bank account or any business with employees, and useful for keeping your SSN private.
Cost$0, never pay a service
TimeAbout 10 minutes online
WhereIRS.gov, directly
Best forSeparate business banking
LLC (limited liability company)
State · ongoingA state-registered entity separate from you. Run correctly, with separate accounts and records, it protects personal assets from most business debts and lawsuits.
Cost$40 to $500 setup, $0 to $800 a year
Time1 to 4 weeks
ProtectionPersonal assets separated
Best forReal risk, partners, meaningful revenue
Liability risk is the main reason to form an LLC, so the case builder starts there. Physical services, rentals, and customers visiting your location raise the chance of injury or property claims. Digital work done online usually carries far less exposure. Personal assets matter too, since a shield is more valuable when you have savings, home equity, or investments to protect. A partner changes the picture sharply, because an informal partnership can make each owner liable for the other. Revenue affects whether ongoing state fees feel reasonable or wasteful. A brand name points toward a DBA rather than a full company. Answer the seven questions below, and the suggested setup appears right away. You can override it if your situation includes something the questions miss. The scale at the top of the page tilts to match your result.
Tell the sheet your case
Your situation.
0 of 7 answered1.What kind of work do you do?If several, pick the biggest
2.Where do you meet customers or clients?Physical premises change liability exposure
3.Do you have personal assets you would want to protect?Home, savings, investments, retirement
4.Do you have a business partner?Anyone with an ownership share
5.What is your monthly gross revenue right now?Rough is fine
6.Do you want to operate under a brand name?A name that is not your legal name
7.What state are you in?Sets the range of LLC fees and paperwork
The federal EIN is free everywhere, but almost every other cost depends on your state. LLC formation fees commonly range from about forty to five hundred dollars. Annual reports, renewal fees, and minimum taxes can add nothing at all or several hundred dollars each year. California is the widely cited example, with an LLC franchise tax of eight hundred dollars a year regardless of income. A few states, including New York, also require newspaper publication that can cost hundreds or more. DBA registration usually costs far less, though some states require publication as well. Those recurring costs matter more than the setup fee over several years. The estimator below compares illustrative totals for a sole proprietorship, a DBA, and an LLC. Choose a fee profile and a time span to see how the gap grows. Always confirm exact figures with your Secretary of State before filing.
How the gap grows over time
Illustrative only. Profiles use rounded example fees, not any state’s official schedule. Publication requirements in New York and a few other states can add a one-time cost on top. Check your Secretary of State for exact numbers.
Order matters once you know which tools you need. For a sole proprietor, the EIN can come first, since it takes minutes and opens the door to business banking. If you want a brand name, register a DBA with your state or county before opening an account in that name. An LLC comes before its EIN, because the IRS application asks what type of entity you are. After the state approves the Articles of Organization, apply for the EIN and then open the bank account. Draft an operating agreement even when your state does not require one. Every flow below lists the steps in order, with common traps flagged. The flows that match your suggested setup are highlighted automatically. Mark each one as done when you finish it. Your progress saves in this browser for the next visit.
Steps in order
Go to the IRS EIN page on IRS.gov during its online hours. Apply directly; never pay a third-party service to file for you.
Choose the entity type that matches you, such as sole proprietor, or limited liability company if the LLC is already formed.
Enter the responsible party, usually you, with your name and SSN.
Answer the reason for applying, confirm, and download the confirmation letter right away. The IRS will not email it.
Save the letter with your records and use the EIN for tax forms, bank accounts, and client paperwork.
Search your state business-name database and your county records to confirm the name is available.
Find the DBA or fictitious business name form. Depending on your state, it is filed with the Secretary of State or the county clerk.
File the form and pay the fee, often $10 to $100. Some states also require a newspaper notice after filing.
Keep the DBA certificate with your records. Banks usually ask for it before opening an account in the trade name.
Put the renewal date in your calendar. Many DBAs expire after about five years.
Choose a name and confirm it is available. It must include a designator such as LLC.
Name a registered agent who receives legal notices. You can serve yourself if you have an in-state address and keep regular hours.
File Articles of Organization with the Secretary of State and pay the formation fee.
Apply for an EIN for the LLC once the state approves the filing.
Draft an operating agreement, even if your state does not require one.
Open a business bank account under the LLC and keep business and personal money fully separate.
Calendar the annual report and any franchise tax deadlines so the LLC stays in good standing.
Filing is a beginning rather than an ending, especially for an LLC. Most states expect an annual or biennial report, and missing it can lead to administrative dissolution. Business and personal money must stay in separate accounts, because mixing them weakens the liability shield. Sole proprietors and single-member LLCs usually report income on Schedule C, while multi-member LLCs file a partnership return. The IRS recommends keeping business records for at least three years, and often longer. Revisit your structure whenever revenue grows meaningfully, a partner joins, or risk increases. A choice that fits at five hundred dollars a month may not fit at five thousand. Free help is available from the SBA, SCORE mentors, and Small Business Development Centers. Your field sheet below collects the plan in one place. Copy it before you speak with an adviser or file anything.
What comes next
Annual state filings
Most states require an annual or biennial LLC report confirming the registered agent and members.
→Check your report deadline
→Fees often $10 to $300
→Missing it can dissolve the LLC
Business taxes
Structure changes what you file, not necessarily how much you owe.
→Sole prop: Schedule C
→Single-member LLC: usually Schedule C
→Multi-member LLC: Form 1065 and K-1s
Bank separation
Critical for LLCs: every business dollar in a business account.
→Business checking and card
→No personal spending on either
→Pay yourself by documented transfer
Franchise tax and fees
Some states charge LLCs every year regardless of income.
→Look up your state amount
→Budget for it in year one
→Weigh it before forming
Records to keep
Keep business records for at least three years, often longer.
→Income: invoices, 1099s, deposits
→Expenses: receipts, statements
→Mileage log for vehicle use
When to revisit
The right structure at $500 a month may change at $5,000.
→Revenue grows meaningfully
→You add employees or partners
→Liability exposure increases
Ask before you pay anyone
Everything on one page
Questions readers ask
No. You become a sole proprietor automatically when you earn self-employment income. An LLC is optional and is worth considering when liability risk, a partner, or meaningful revenue make its fees worthwhile.
For most single-owner side businesses, no. A single-member LLC is usually taxed like a sole proprietorship by default. Other tax elections exist, but they are worth discussing with a tax professional first.
Yes. The IRS does not charge for an EIN, and you can apply directly on IRS.gov. Services that charge a fee are only filling out the same free form.
Yes. Many owners start as sole proprietors and form an LLC when risk or revenue grows. Check with the IRS whether you need a new EIN, and update bank accounts, contracts, and licenses.
Work through your case in the full guide
Nine sections, a seven-question case builder, step-by-step filing flows, and a printable field sheet. Everything stays on your device.
Open the guide →General information only, not legal, tax, financial, or business advice. This guide does not form entities, file paperwork, or quote official state fees. State rules, fees, and processes change, so confirm current requirements with your Secretary of State and the IRS, or a qualified attorney or tax professional, before you file.