Sole Proprietorships in California

A sole proprietorship is what you have by default when you start working for yourself and file nothing. There is no formation document, no Secretary of State filing, no $800 annual tax, and no separate return — business income and expenses go on Schedule C with your personal return.

For a genuinely small operation, that simplicity is worth real money in California, where an LLC costs $800 a year before it earns a dollar. Most advice pushes new businesses to form an entity immediately. Frequently that advice is premature.

The structure stops being appropriate at identifiable points, and this page covers both — when it works, and when it costs more than it saves. We advise self-employed clients in Temecula, Murrieta, San Diego, Riverside, and San Bernardino.

How You Are Taxed

Net profit from Schedule C is subject to two layers:

Income tax at your ordinary rates — federal brackets to 37%, plus California to 13.3%.

Self-employment tax on all net earnings: 15.3% up to the Social Security wage base, 2.9% Medicare above it, plus 0.9% additional Medicare over $200,000 single or $250,000 joint. Half is deductible against income tax, which softens but does not eliminate it.

Self-employment tax is what surprises people leaving employment. As an employee, your employer paid half of FICA. Self-employed, you pay both halves — an immediate 7.65% increase on the same earnings.

Estimated payments are due quarterly to both the IRS and the FTB. Underpayment penalties on the first year of self-employment are among the most common avoidable costs we see, because withholding no longer covers the liability.

The Deduction That Does Not Cross the State Line

Federal law allows a Section 199A deduction of up to 20% of qualified business income, made permanent by OBBBA. It is subject to income thresholds and to limitations for specified service businesses.

California has no equivalent. Full Schedule C profit is taxed at California rates with no comparable deduction. A sole proprietor modeling an effective rate on the federal calculation alone will understate the real burden substantially — which is one reason the “California costs more than you think” theme runs through every structure on this site.

Related divergences: bonus depreciation is unavailable in California, and Section 179 is capped at $25,000 against $2.5 million federally. Equipment purchases that are fully expensed federally are depreciated over years on the California return.

Deductions Worth Getting Right

• Home office — the simplified method allows $5 per square foot up to 300 square feet; the actual expense method allocates real costs and is often larger. Exclusive and regular business use is required.
• Vehicle — standard mileage or actual expenses, with a contemporaneous mileage log. This is heavily examined and rarely defensible when reconstructed after the fact.
• Self-employed health insurance — an above-the-line deduction for premiums covering you, your spouse, and dependents
• Retirement plans — a SEP-IRA or solo 401(k) allows substantially larger contributions than an IRA, and the solo 401(k) permits both employee deferral and employer contribution
• Qualified business income — federal only, as above

Schedule C is examined more than most return types, particularly where losses recur across years, deductions are large relative to receipts, or the business is cash-intensive. The hobby loss rules under Section 183 allow the IRS to disallow losses from an activity not engaged in for profit. Business plans, separate bank accounts, and genuine profit-seeking behavior are what distinguish a business from a hobby. See IRS audits.

What You Give Up

There is no liability shield. Business debts are personal debts. A judgment against the business reaches your house, your savings, and your personal accounts. Insurance manages some of this risk, but it is not the same protection an entity provides.

You cannot bring in owners. Adding a partner converts the business into a general partnership, usually without anyone filing anything — and general partners are personally liable for each other’s business obligations.

No employment tax planning. All net profit is subject to self-employment tax, with none of the salary-and-distribution split an S corporation allows.

No QSBS. Only C corporation stock can qualify for the Section 1202 exclusion.

When It Stops Making Sense

Three thresholds usually trigger the conversation:

Profit approaching $60,000 to $80,000 above a reasonable salary. Below that, an S election’s payroll and compliance costs typically exceed the self-employment tax savings — especially with California’s 1.5% franchise tax on S corporation income. Above it, the arithmetic flips.

Meaningful liability exposure. Employees, physical premises, contracting work, products, or anything where a claim could exceed insurance limits.

Outside money or partners. Investors will not buy into a sole proprietorship, and adding a partner without a written agreement creates a general partnership with joint personal liability.

Our entity formation page compares the options and the California costs of each.

Local Requirements That Still Apply

No state formation filing does not mean no obligations:

• Fictitious business name statement — filed with the county if operating under a name other than your own, with publication required
• City business license — Temecula, Murrieta, San Diego, and most Southern California cities require one
• Seller’s permit from CDTFA if selling tangible goods
• EDD registration within 15 days of paying $100 in wages in a quarter — see EDD
• Professional licensing where the work requires it

Hiring anyone raises worker classification exposure under California’s ABC test. Treating a worker as a contractor who does not meet it produces EDD assessments for unpaid payroll taxes, penalties, and interest.

Recordkeeping That Survives an Examination

Schedule C filers carry the burden of substantiating every deduction, and the records that satisfy that burden have to exist before the examination, not after.

The foundation is a separate business bank account. Running business income and expenses through a personal account is the single most damaging habit a sole proprietor can have — it makes every deduction harder to prove, invites the examiner to treat unexplained deposits as unreported income, and supports a hobby-loss argument if losses recur.

Beyond that: contemporaneous mileage logs recording date, destination, purpose, and distance; receipts for expenses with the business purpose noted; and, for the home office, documentation of the square footage and its exclusive business use.

Certain categories carry strict substantiation requirements under Section 274 — travel, meals, and vehicle expenses among them — and the ordinary rule permitting reasonable estimates where records are imperfect does not apply to them. For those categories, missing records generally mean a disallowed deduction regardless of how genuine the expense was.

Frequently Asked Questions

Do I need to register a sole proprietorship in California?

Not with the Secretary of State. You may still need a fictitious business name statement, a city business license, a seller’s permit, and EDD registration if you have employees.

Do I owe the $800 California franchise tax?

No. That applies to LLCs and corporations. This is the main cost advantage of remaining a sole proprietor.

How much is self-employment tax?

15.3% up to the Social Security wage base and 2.9% above it, plus 0.9% additional Medicare over $200,000 single or $250,000 joint. Half the base amount is deductible against income tax.

Does California allow the 20% QBI deduction?

No. Section 199A is federal only, so full Schedule C profit is taxed at California rates.

Will forming an LLC lower my taxes?

By itself, no — a single-member LLC is disregarded and taxed identically, while adding $800 a year plus possible gross receipts fees. Tax savings come from an S election, not from the LLC.

When should I incorporate?

Usually when profit exceeds a reasonable salary by roughly $60,000 to $80,000, when liability exposure becomes material, or when you take on partners or investors.

What if I have been operating without a business license?

Cities generally allow retroactive registration with penalties. It is far cheaper to resolve proactively than after an enforcement contact.

Can I deduct a loss from my business against other income?

Generally yes, if the activity is engaged in for profit and you are at risk for the amounts. Recurring losses invite hobby-loss scrutiny under Section 183, and excess business loss limitations can defer part of a large loss to a later year.

Do I need an EIN as a sole proprietor?

Not unless you have employees or a retirement plan requiring one, but obtaining one is free and lets you avoid giving your Social Security number on every Form W-9 a client sends. For most self-employed people that privacy benefit alone justifies it.

How much should I set aside for taxes?

It depends on total household income, but self-employment tax alone runs about 15.3% before any income tax, and California adds its own layer with no QBI equivalent. Running an actual projection early in the year is far better than a rule of thumb, particularly in the first year when there is no prior-year safe harbor to rely on.

Know When to Change Structure

Staying a sole proprietor is often the right answer early, and staying one too long is a common and expensive mistake. The signals are quantifiable — profit level, liability exposure, and whether anyone else is coming into the business.

Pietro Canestrelli holds an LL.M. in Taxation and advises self-employed clients on structure, deductions, estimated payments, and Schedule C examination defense. Schedule a consultation, or review our entity formation and tax planning services.