If you're running a business and haven't filed anything with your state, you're already a sole proprietorship. You didn't choose that status, it's just the default. An LLC works the other way: you form it on purpose, with an actual state filing.
A sole proprietorship costs nothing to start and gives you no separation between you and your business. An LLC costs a filing fee and some paperwork, and in exchange it puts a legal wall between your business's debts and your personal house, car, and savings.
For federal income tax purposes, a single-member LLC is treated exactly like a sole proprietorship by default, so taxes usually aren't the deciding factor. Liability, paperwork, and how the outside world treats your business are.
Quick highlights:
A sole proprietorship has no formation step. You're automatically one the moment you start doing business under your own name without registering anything else.
An LLC requires a state filing (Articles of Organization) and typically an operating agreement.
A single-member LLC's default federal tax treatment is identical to a sole proprietorship's. Forming an LLC doesn't change your tax bill by itself.
The real difference is liability protection: a sole proprietorship offers none, an LLC creates a shield around your personal assets in most instances.
Four moments push people from sole prop to LLC: liability risk, a co-founder, raising money, or a bank or client requirement.
What is a sole proprietorship?
A sole proprietorship is the default legal status for a one-owner, unincorporated business. The IRS puts it plainly: "A sole proprietor is someone who owns an unincorporated business by themselves." There's no registration, no state filing, no separate legal entity. You and the business are, legally, the same thing.
The Small Business Administration describes the tradeoff this way: "A sole proprietorship is easy to form and gives you complete control of your business. You're automatically considered to be a sole proprietorship if you do business activities but don't register as any other kind of business."
That ease comes at a cost. Because there's no legal separation between you and the business, your personal assets are exposed if the business runs into debt or gets sued.
The SBA is direct about this too: "your business assets and liabilities are not separate from your personal assets and liabilities. You can be held personally liable for the debts and obligations of the business."
What is an LLC?
An LLC, or limited liability company, is a business structure you form with your state, not one you fall into by default. Filing Articles of Organization creates a legal entity that's separate from you personally, even if you're the only owner.
That separation is the entire point. As the SBA puts it, "LLCs protect you from personal liability in most instances, your personal assets (like your vehicle, house, and savings accounts) won't be at risk in case your LLC faces bankruptcy or lawsuits."
An LLC can have one owner (a single-member LLC) or more than one (a multi-member LLC). This piece focuses on the single-member case, since that's the direct comparison point against a sole proprietorship. If you're weighing one owner against several, the single-member vs. multi-member LLC comparison covers that decision specifically.
Sole proprietorship vs. LLC: the differences at a glance
Sole Proprietorship | LLC | |
|---|---|---|
Formation required | None. Automatic by default. | State filing (Articles of Organization) plus typically an operating agreement. |
Liability protection | None. Owner and business are legally the same. | Personal assets protected in most instances. |
Default federal tax treatment | Schedule C on your personal Form 1040. | Same as a sole proprietorship by default (single-member LLC), unless you elect otherwise. |
Formation cost | None. | State filing fee (varies by state), plus possible ongoing state fees. |
Ongoing paperwork | Minimal. Schedule C and Schedule SE at tax time. | State filing plus, in many states, annual reports or franchise tax. |
Banking and credibility perception | Often read as informal. Some banks and vendors won't work with an unincorporated business at all. | Generally read as a real, established business entity. |
Which of these matters most depends on which of the four moments below applies to you.
Tax treatment is the same by default
This is the most common misconception in the whole comparison, so it gets its own section. Forming an LLC does not change how you're taxed. Not automatically, anyway.
The IRS spells this out for single-member LLCs specifically: "For income tax purposes, an LLC with only one member is treated as an entity disregarded as separate from its owner, unless it files Form 8832 and affirmatively elects to be treated as a corporation." So the IRS ignores the LLC wrapper for tax purposes unless you go out of your way to ask for something different.
The self-employment tax mechanics carry over too. The IRS says the same about self-employment tax: "An individual owner of a single-member LLC that operates a trade or business is subject to the tax on net earnings from self employment in the same manner as a sole proprietorship." Same Schedule C, same Schedule SE, same self-employment tax math either way.
So if someone tells you to form an LLC "for the tax benefits," ask them which election they mean. The LLC itself doesn't create a tax advantage.
Any tax difference comes from a separate election, like choosing S-corp tax treatment. A sole proprietorship can't make that election at all; an LLC can. But that's a distinct decision layered on top of entity choice, not a default feature of forming an LLC.
Liability protection: the real difference
If tax treatment is a wash, liability protection is where the two structures diverge.
As a sole proprietor, there's no legal line between you and your business. A lawsuit against the business is, functionally, a lawsuit against you. A judgment can reach your personal bank account, your car, your house. The SBA's language on this is unambiguous: you "can be held personally liable for the debts and obligations of the business."
An LLC changes that. It's a separate legal entity, so in most instances, a claim against the business stays a claim against the business. The SBA hedges this appropriately too: LLCs protect you "in most instances," not absolutely and not in every case.
Piercing the LLC shield is possible if you mix personal and business finances or skip basic formalities like a separate bank account. But structurally, the protection exists for an LLC and doesn't exist at all for a sole proprietorship.
Formation cost and paperwork
A sole proprietorship costs nothing to start because there's nothing to file. You're automatically one the moment you start doing business under your own name, per the SBA language above.
An LLC requires an actual filing. You submit Articles of Organization to your state, usually alongside a filing fee that varies by state. Most LLCs also draft an operating agreement, which isn't always legally required but spells out ownership, management, and what happens if the business changes hands.
After formation, many states require an annual report or an ongoing franchise tax to keep the LLC in good standing, on top of the one-time filing.
None of this is expensive relative to what the entity protects, but it's not nothing either, and it's the most concrete cost difference between the two structures. If you form an LLC, you'll likely also need to decide whether you need a new EIN. Our EIN for an LLC guide walks through when that applies even for a single owner with no employees.
Credibility and banking perception
Staying a sole proprietorship isn't only a legal question. It's a perception one too.
An LLC generally reads as a more established, more permanent business than an unincorporated sole proprietorship operating under a DBA. That perception shows up in practical ways.
Some banks and vendors treat a formal legal entity as a baseline requirement, not a nice-to-have. They'll ask for the paperwork to prove it, typically your Articles of Organization or an EIN confirmation letter, and won't open a business account or sign a contract with an unincorporated business at all.
That's not a universal rule, and plenty of sole proprietorships bank and contract just fine. But it's a real enough pattern that "the bank or client wants an LLC" is one of the four moments below where forming one stops being optional.
When should you form an LLC?
There's no single income threshold or business age where an LLC suddenly becomes mandatory. But four situations reliably tip the decision.
You're taking on real liability risk. If your work could plausibly result in someone getting hurt, property getting damaged, or a client suing over the outcome, the liability protection an LLC provides starts to outweigh the paperwork. This matters more in some industries (construction, food service, anything client-facing with contracts) than others.
You're bringing on a co-founder. A sole proprietorship has exactly one owner by definition, that's what the IRS's own definition means by "owns... by themselves." Adding a second owner isn't an option within a sole proprietorship. It requires forming a different structure, whether that's a multi-member LLC, a partnership, or a corporation.
You want to raise outside money. A sole proprietorship has no legal mechanism to issue equity or membership interests to an investor. If you're planning to bring in outside capital in exchange for a stake in the business, you need an entity that can actually issue that stake, which a sole proprietorship structurally cannot do.
That's often the point where the entity conversation moves beyond LLC vs. sole proprietorship into C corp vs. S corp, since investors typically want to see a specific corporate structure.
A bank or client requires it. Some financial institutions and larger business clients simply won't work with an unincorporated business, full stop. If you've hit that wall, or expect to, forming an LLC (or another entity) is a precondition, not a preference.
If none of these apply yet, staying a sole proprietorship is a reasonable, low-cost default. The moment one of them does, the calculus changes.
What it comes down to
A sole proprietorship is fine, often for a long time. There's no filing, no fee, and no ongoing paperwork, and for a low-risk, solo business, that's a reasonable place to stay.
An LLC earns its cost once real liability risk shows up, once a co-founder enters the picture, once you want to raise outside money, or once a bank or client requires a formal entity.
Tax treatment won't push you either way: a single-member LLC is taxed the same as a sole proprietorship by default. The decision comes down to liability, paperwork, and who you need to look credible to, not the IRS.
If you're past the sole-proprietorship stage and weighing structure specifically, single-member vs. multi-member LLC and do you need an EIN for an LLC cover the next two questions that tend to follow.
FAQs
It depends on your liability exposure and plans, not a universal ranking. A sole proprietorship is simpler and free to maintain if your risk is low and you're not adding owners or outside investors. An LLC costs more upfront and carries ongoing paperwork, but it protects your personal assets in most cases and tends to be treated as more credible by banks and clients.
No separation between personal and business liability, so personal assets are exposed to business debts and lawsuits. It also can't have more than one owner, can't issue equity to investors, and some banks or clients simply won't work with an unincorporated business.
Not compared to a single-member LLC. Both structures use the same default federal tax treatment, Schedule C on your personal return and Schedule SE for self-employment tax. Forming an LLC doesn't change this by itself, only a separate tax election (like choosing S-corp treatment) would.
Yes. Most people who start as a sole proprietorship convert to an LLC later, usually when one of the trigger points above shows up. The process means filing Articles of Organization with your state and, in most cases, getting a new EIN.
It's a formation step, not a conversion of an existing legal entity, since a sole proprietorship isn't a separate entity to begin with. It's worth revisiting your bank accounts and existing contracts around the same time too, since those were opened under your name as a sole proprietor and may need to move to the new LLC.
There's no single income number where an LLC becomes worth it. The trigger points above turn on liability exposure, ownership structure, and who you're selling to or banking with, not revenue. Income often surfaces those triggers rather than causing them: more revenue tends to mean more liability exposure and more client contracts that specify a formal entity.
Not universally, but it depends on the bank. Some banks and financial providers require a business to be a formally incorporated entity before opening an account, and a sole proprietorship doesn't qualify at those institutions. Others work with sole proprietorships directly. Check with the specific bank you're considering before assuming either way.