LLC vs. Sole Proprietorship for a Side Business (US)

Every side business starts as a sole proprietorship by default, whether or not anyone decided that on purpose — it's simply what "an individual doing business without registering anything else" is called. The question isn't whether to have a business structure, it's whether the default one is still the right fit once real money, real clients, or real liability start showing up.

What Each Structure Actually Is

A sole proprietorship is the default status of anyone earning business income without separate registration — no filing, no fee, no separate legal entity. Income and expenses get reported directly on the owner's personal tax return (Schedule C), and legally, the business and the individual are the same entity, which means business debts and lawsuits can reach personal assets like a car, a home, or personal savings.

An LLC (limited liability company) is a state-registered business entity that creates a legal separation between the business and its owner. For tax purposes, a single-member LLC is by default treated identically to a sole proprietorship — still reported on Schedule C, no automatic tax change — but legally, it generally shields personal assets from business debts and most lawsuits arising from the business, provided the separation is genuinely maintained (a separate bank account, no mixing of funds).

The Real Cost Difference Across States

LLC formation isn't a fixed national cost — it's set individually by each state, and the difference is large enough to change the decision entirely depending on where the business is based. Texas charges a one-time $300 filing fee for a Certificate of Formation, and most small LLCs owe no franchise tax at all, since Texas exempts businesses under a revenue threshold (in the millions of dollars) from the state's franchise tax. California charges only a $70 filing fee upfront, but requires an $800 minimum annual franchise tax on every LLC regardless of whether it made a profit that year.

Over five years, that's $300 total in Texas versus $4,070 in California for functionally the same legal protection — a difference large enough that some California-based side hustlers deliberately stay sole proprietors until revenue justifies the annual cost, while the same business in Texas might form an LLC almost immediately given how low the one-time cost is.

Step-by-Step: Deciding Which Fits Your Situation

Start by honestly assessing liability exposure: does the business involve client contracts that could go wrong, physical products that could injure someone, professional advice that could be blamed for a loss, or employees or contractors working under the business? A low-risk service like freelance writing or virtual assistance carries meaningfully less exposure than a business selling physical goods or giving financial, legal, or medical guidance.

Next, check your specific state's LLC filing fee and ongoing requirements — not a national average, since the range runs from under $50 in some states to several hundred dollars plus annual fees in others. Compare that annual cost against current side-business revenue: an $800-a-year state fee is a rounding error against $80,000 in revenue but a real bite against $4,000.

Finally, check whether a client, platform, or contract explicitly requires a formal business entity to work with you — some corporate clients and marketplaces require an LLC or corporation before they'll issue a contract, which can force the decision regardless of the cost-benefit math above.

What Doesn't Change Between the Two

Federal tax treatment is identical by default: a single-member LLC and a sole proprietorship both report business income and expenses on Schedule C, both pay self-employment tax on net profit, and both use the same estimated quarterly tax process. Forming an LLC does not, by itself, reduce federal tax owed — that requires a separate election (commonly S-corp taxation) layered on top of the LLC, which brings its own added complexity and cost and is a decision generally worth a conversation with a tax professional once profit is large enough to make it worthwhile.

When an S-Corp Election Starts to Make Sense

Once profit grows large enough, some LLC owners file a separate election to be taxed as an S-corporation, which changes the self-employment tax math significantly. Under the default treatment, a $90,000 net profit owes self-employment tax on 92.35% of that amount at 15.3%, or about $12,717. Under an S-corp election, the owner pays themselves a "reasonable salary" — say $50,000 — subject to payroll tax at the same 15.3% rate ($7,650), and takes the remaining $40,000 as a distribution that isn't subject to self-employment or payroll tax at all, only ordinary income tax. That's roughly $5,067 saved in a single year purely on the tax structure.

This isn't free, though: an S-corp election adds real ongoing costs — running actual payroll for the owner's salary, additional tax filings, and stricter recordkeeping — and the salary has to be "reasonable" for the work performed, a standard the IRS actively scrutinizes precisely because this savings strategy is well known. Most tax professionals suggest the added complexity only pays for itself once net profit is comfortably above roughly $40,000 to $60,000 a year, and it's a decision worth making with a CPA rather than as a self-service filing.

The Short Version

A sole proprietorship costs nothing and offers no liability separation; an LLC adds that separation at a state-specific cost ranging from a few hundred dollars total (Texas) to nearly $1,000 a year (California). Assess real liability exposure first, check your specific state's actual fee structure rather than a national average, and remember that forming an LLC doesn't change federal tax filing by default. Businesses with real liability risk, employees, or a client requiring a formal entity usually justify the cost; a low-risk side hustle just getting started often doesn't need it yet.

FAQ

Educational resource only, not legal or tax advice. Formation fees, franchise taxes, and liability rules vary by state and change over time — confirm current requirements with your state's Secretary of State office and consult a licensed attorney or CPA before choosing a business structure. See the IRS's overview of business structures and the U.S. Small Business Administration's guide to choosing a business structure for authoritative, current guidance.