Schedule C Explained: A Plain-English Guide for Self-Employed Filers

If you're self-employed — whether you freelance, drive for a rideshare app, run an Etsy shop, or do contract work on the side — there's one IRS form you need to understand: Schedule C. It's how you report your business income and expenses, and it's attached to your regular 1040 tax return.

The form itself is straightforward once you know what goes where. Here's a plain-English walkthrough.

What is Schedule C?

Schedule C (Profit or Loss from Business) is the IRS form for sole proprietors — meaning anyone who runs a business that isn't set up as a corporation or formal partnership. That includes:

• Freelancers and consultants
• Rideshare and delivery drivers (Uber, Lyft, DoorDash, Instacart)
• Independent contractors who receive 1099-NEC forms
• Online sellers (Etsy, eBay, Amazon resellers)
• Sole proprietors with or without an LLC
• Side hustlers earning income outside a W-2 job

If you earned $400 or more in net self-employment income during the year, you're required to file Schedule C and pay self-employment tax.

What's the difference between a 1099 and Schedule C?

People mix these up all the time, so let's clear it up.

A 1099 is an information form — it tells you (and the IRS) how much someone paid you. The two most common ones for self-employed people are:

• 1099-NEC: Reports non-employee compensation of $600 or more from a single client
• 1099-K: Reports payment card and third-party network transactions (Venmo, PayPal, Stripe, etc.)

Schedule C is where you report all your self-employment income — including income you didn't get a 1099 for — and subtract your business expenses. You might have five 1099s, but they all flow into one Schedule C. The bottom line of your Schedule C (profit or loss) then flows onto your 1040.

What can you deduct on Schedule C?

This is where things get good. The IRS lets you deduct any expense that is "ordinary and necessary" for your business. That phrase sounds vague, but in practice it means: if it's a normal cost of doing the kind of work you do, and you need it to do that work, it's deductible.

Common Schedule C deductions

• Vehicle expenses: You can use the IRS standard mileage rate (70 cents per mile for 2026) or track actual expenses (gas, insurance, maintenance, depreciation). You must keep a mileage log either way.
• Home office: If you have a dedicated space used exclusively for business, you can deduct a portion of rent/mortgage, utilities, and insurance — or use the simplified method ($5/sq ft, up to 300 sq ft = $1,500 max).
• Supplies and equipment: Tools, materials, computers, phones — anything you buy to do your work. Items over a certain threshold may need to be depreciated, but Section 179 lets most small businesses deduct the full cost in year one.
• Software and subscriptions: QuickBooks, Adobe, Canva, your website hosting, project management tools — all deductible.
• Phone and internet: The business-use percentage. If you use your phone 60% for business, you deduct 60% of the bill.
• Professional development: Courses, certifications, conferences, and books related to your field.
• Advertising and marketing: Website costs, business cards, online ads, social media tools.
• Insurance: Business liability insurance, professional indemnity, errors & omissions.
• Health insurance premiums: If you're self-employed and not eligible for a spouse's employer plan, you can deduct your premiums — though this goes on the 1040 as an adjustment, not directly on Schedule C.
• Subcontractors: If you pay someone $600+ to help with your business, that's deductible (and you'll need to send them a 1099-NEC).

How does self-employment tax work?

This catches a lot of first-time self-employed filers off guard. When you work a W-2 job, your employer pays half of your Social Security and Medicare taxes. When you're self-employed, you pay both halves — that's the self-employment (SE) tax.

The rate is 15.3% of your net self-employment income:

• 12.4% for Social Security (on the first $176,100 of combined wages + SE income in 2026)
• 2.9% for Medicare (no cap)
• 0.9% additional Medicare tax on SE income above $200,000 (single) or $250,000 (married filing jointly)

The silver lining: you get to deduct half of your SE tax as an adjustment to income on your 1040, which reduces your taxable income. And your SE tax is only calculated on your net profit — meaning after your Schedule C deductions.

This is exactly why tracking deductions matters so much. Every legitimate dollar you deduct saves you both income tax and 15.3% in SE tax.

Do I need to make quarterly estimated payments?

Probably. If you expect to owe $1,000 or more in taxes for the year (income tax + SE tax combined), the IRS expects you to pay as you go by making quarterly estimated tax payments using Form 1040-ES.

The four quarterly deadlines for 2026:

1. April 15 — for income earned January through March
2. June 15 — for April and May
3. September 15 — for June through August
4. January 15, 2027 — for September through December

Missing these deadlines can result in an underpayment penalty, even if you file on time and pay everything by April 15. The penalty isn't huge, but it's completely avoidable.

Common mistakes to avoid

1. Not reporting all income

The IRS gets copies of your 1099s. If income appears on a 1099 but not on your return, expect a notice. Also remember: income you didn't receive a 1099 for is still taxable. Cash payments, Venmo transfers, direct deposits below the 1099-K threshold — it all counts.

2. Mixing personal and business expenses

If you use your car for both personal and business driving, only the business portion is deductible. Same with your phone, internet, and home office. The IRS won't challenge reasonable estimates, but "100% business use" on a personal cell phone is a red flag.

3. No mileage log

If you're claiming vehicle expenses — especially at the standard mileage rate — you need a contemporaneous record: date, destination, business purpose, and miles driven. Apps like MileIQ or Everlance make this automatic. Without a log, the IRS can disallow the entire deduction in an audit.

4. Forgetting about self-employment tax

New freelancers often calculate their taxes based only on their income tax bracket and forget the additional 15.3%. If you made $60,000 in net self-employment income, your SE tax alone is about $8,478 — on top of your regular income tax.

5. Not separating business finances

You don't technically need a business bank account as a sole proprietor, but having one makes everything easier — cleaner records, simpler bookkeeping, fewer headaches at tax time, and a much stronger position if you're ever audited.

When should you get help with Schedule C?

Plenty of people file their own Schedule C without issues, especially if their situation is straightforward — one income stream, clear expenses, no employees. But it's worth talking to a tax professional if:

• You have multiple income streams or clients in different states
• You're not sure what's deductible (and want to maximize it without getting in trouble)
• You also have a W-2 job and self-employment income and aren't sure how they interact
• You're behind on estimated payments and want to figure out the penalty exposure
• You're wondering whether it's time to switch to an S-corp election to save on SE tax
• You have a net loss and want to know how it affects your overall return
• You just want to stop worrying about whether you're doing it right

A good tax preparer doesn't just fill in forms — they catch deductions you'd miss, flag potential issues, and save you more than they cost.

The bottom line

Schedule C is just how the IRS asks you to organize your self-employment income and expenses. The form itself isn't complicated — the challenge is staying organized throughout the year so the numbers are ready when tax time comes. Track your income, log your mileage, keep your receipts, and set aside money for taxes quarterly. Do that and you're ahead of most self-employed filers.

Connor Gee is a tax preparer and co-founder of Verde Tax Returns, a mother-and-son bookkeeping and tax preparation firm based in Aurora, CO. Verde serves clients in all 50 states.