Sole Proprietorship: What It Is, How It's Taxed and When to Choose One

I've pulled this from the IRS pages on sole proprietorships and self-employment tax and the U.S. Small Business Administration's guide to business structures, all checked in October 2026. I've run my own business for a long time, and the sole proprietorship is where most of us start, often without realising we've chosen anything.

What a sole proprietorship means in practice

The IRS defines a sole proprietor as someone who owns an unincorporated business by themselves. The SBA spells out the trade-off: it's easy to form and gives you complete control, but it doesn't create a separate business entity. Your business assets and liabilities aren't separate from your personal ones, so you can be held personally liable for the debts and obligations of the business.

Feature	Sole proprietorship
Owners	One person
How you create it	Automatically, by doing business without registering another structure
Liability	Unlimited personal liability
Tax	Self-employment tax and personal income tax
Business name	You can still get a trade name
Raising investment	Hard: you can't sell stock and banks are hesitant to lend

The LLC detail that changes everything

Here's the line on the IRS page most people skip. If you're the only member of a domestic limited liability company and you elect to treat the LLC as a corporation, you're not a sole proprietor. A single-member LLC that doesn't make that election is a different story for tax, so check what you've elected before you assume which forms are yours. My LLC vs sole proprietorship comparison goes through the choice in more detail.

The tax forms a sole proprietor files

The IRS lists the forms you may need. Not every business needs all of them: the employment forms only apply once you hire people.

Tax	Form
Income tax	Form 1040 with Schedule C, Profit or Loss from Business
Self-employment tax	Schedule SE (Form 1040)
Estimated tax	Form 1040-ES
Social Security, Medicare and income tax withholding for employees	Form 941, 943 or 944
Reporting employee wages	Form W-2 to employees and W-3 to the Social Security Administration
Federal unemployment tax	Form 940

Self-employment tax: the 15.3% people forget

The self-employment tax rate is 15.3%, made up of 12.4% for Social Security and 2.9% for Medicare. It's how sole proprietors pay into Social Security and Medicare, because there's no employer withholding it for them. You have to pay it and file Schedule SE if your net earnings from self-employment were $400 or more, as of October 2026.

There's one bit of relief: you can deduct the employer-equivalent portion of your self-employment tax when you work out your adjusted gross income, which wage earners can't do with their own Social Security and Medicare taxes. Because nobody withholds tax for you, most sole proprietors also pay estimated tax during the year. My estimated tax payments guide explains how that works.

How it compares with other structures

Structure	Owners	Liability	Tax
Sole proprietorship	One person	Unlimited personal liability	Self-employment tax and personal tax
Partnership	Two or more people	Unlimited unless structured as a limited partnership	Self-employment tax (except limited partners) and personal tax
LLC	One or more people	Owners aren't personally liable	Self-employment tax and personal or corporate tax
C corp	One or more people	Owners aren't personally liable	Corporate tax

How to set up as a sole proprietor

1. Start trading. Under the SBA's description, that alone makes you a sole proprietor if you haven't registered another structure.
2. Pick a name. If you trade under anything other than your own name, register a trade name where your state requires it.
3. Check local licences and permits for your type of business.
4. Open a separate business bank account. The SBA notes you'll need an EIN, or a Social Security number if you're a sole proprietorship.
5. Keep records from day one. IRS Publication 583 covers starting a business and keeping records.
6. Set aside cash for income tax and the 15.3% self-employment tax, and pay estimated tax if you need to.

When a sole proprietorship makes sense

The SBA says sole proprietorships can be a good choice for low-risk businesses and owners who want to test their business idea before forming a more formal business. That matches what I see: it's a brilliant way to start, and a risky way to stay if your work carries real liability.

• Good fit: freelancing, consulting, side projects, testing an idea, low-risk services.
• Think twice: anything where a mistake could lead to a big claim, where you'll hold stock or sign big leases, or where you want investors.
• Time to review: when you hire staff, take on larger contracts or start earning enough that the tax treatment of another structure might suit you better.

My verdict

A sole proprietorship is the fastest, cheapest way to get going, and for a lot of small businesses it's the right first step. Just go in with your eyes open: your personal assets are on the line, and the 15.3% self-employment tax is on top of income tax. Keep your business finances separate from day one, put tax aside every month, and review your structure as soon as the stakes go up.

Frequently asked questions

What is a sole proprietorship?

It's a business owned by one person that isn't registered as any other kind of business entity, so the owner and the business are legally the same.

Do I need to register a sole proprietorship?

No. You're automatically a sole proprietor when you do business on your own without registering another structure, though you may need a trade name, licences or permits.

How is a sole proprietorship taxed?

Profit goes on Schedule C with your Form 1040, and you pay self-employment tax of 15.3% if net earnings are $400 or more.

Is a single-member LLC a sole proprietorship?

Not if it has elected to be treated as a corporation. The IRS says the sole member of an LLC that makes that election isn't a sole proprietor.

Can a sole proprietor have employees?

Yes. Once you hire, the IRS lists employment forms such as Form 941 or 944, W-2 and W-3, and Form 940 for federal unemployment tax.

What's the biggest downside of a sole proprietorship?

Unlimited personal liability. Your personal assets aren't separate from the business's debts and obligations.