Introduction
Schedule C is not a standalone business tax return. It attaches to Form 1040 (or is e-filed with it) and reports a sole proprietor's business profit or loss. Get it wrong and the error flows into your income tax, self-employment tax and any deduction built on that profit.
The timing trips people up. In 2027 you file for tax year 2026, with a calendar-year deadline of April 15, 2027. The 2026 Schedule C instructions were still marked as a draft, so check the final versions before you file.
This guide covers who files Schedule C, what to gather, Parts I to V, how profit reaches Form 1040, and what Australian-based owners should watch.
Key Takeaways
- Sole proprietors and eligible single-member LLCs file Schedule C; partnerships and corporations use other forms.
- Line 31 net profit flows to Schedule 1, Form 1040 and Schedule SE.
- Reconcile 1099s against your books before entering income.
- Confirm 2026 forms, thresholds and deadlines on IRS.gov before filing.
What Is Schedule C and Who Needs to File It?
Schedule C (Profit or Loss From Business) is the IRS form you attach to Form 1040 to report income and expenses from a business you run as an individual.
Who uses Schedule C?
Schedule C is for sole proprietors, freelancers, independent contractors and single-member LLCs that haven't elected corporate treatment. A US-formed single-member LLC is generally disregarded for federal income tax unless it files Form 8832. You can hold a W-2 job and still have separate Schedule C income.
The activity must be a business, not a hobby. The IRS looks at profit motive, continuity and regularity, businesslike records, expertise, and whether you depend on the income. Losses from a hobby can't offset other income.
Reporting and self-employment tax are separate questions. Net self-employment earnings of $400 or more generally trigger Schedule SE.
Which activities use another form?
Other structures use different forms:
- Partnerships: Form 1065
- S corporations: Form 1120-S
- C corporations: Form 1120
- Rental and farming: their own schedules
Not every LLC uses Schedule C; it depends on how the LLC is classified.
Run more than one separate business? File a separate Schedule C for each, and don't count any income or expense twice.
How does Schedule C fit a cross-border Australian filing situation?
Schedule C covers US federal reporting only. It doesn't replace your Australian tax residency, worldwide income or foreign income tax offset obligations.
Australia's income year runs 1 July to 30 June, while the US year is the calendar year, so the same income can land in different periods. Check current ATO and IRS guidance for your circumstances.
What to Gather Before Filling Out Schedule C
Collect these before you start:
- Your name, SSN or ITIN, and EIN if you have one
- Business name, address, principal activity and business code
- Accounting method (cash or accrual)
- Profit-and-loss statement and expense ledger
- Receipts, contractor records and fixed-asset details
- Beginning and ending inventory and COGS records
- Mileage log and home-office measurements
Reconcile gross receipts from invoices, bank accounts, payment processors and marketplaces. Don't just copy one information return. For payments made after December 31, 2025, the 1099-NEC and MISC threshold rose to $2,000, but that is a payer reporting threshold. Business income is taxable whether or not you receive a 1099.
Your P&L is a starting point only. It often needs tax adjustments for depreciation, meals, personal use and inventory before the numbers go on the form.
How to Complete Schedule C: Part-by-Part Instructions
Business details and Lines A-J
Fill in the header lines with the basics the IRS needs to identify the activity:
- Principal business or profession and activity code
- Business name, EIN and address
- Accounting method and material participation
- Whether you started or acquired the business this year
- Whether you made payments that required Forms 1099 (and filed them)
Confirm labels against the final 2026 form.
Part I: Income
- Line 1: gross receipts or sales
- Line 2: returns and allowances
- Line 4: COGS, carried from Part III line 42
- Line 5: gross profit
- Line 6: other income
- Line 7: gross income
Form 1099-K Box 1a reports gross payments before fees, refunds and shipping. The IRS treats fees, refunds and shipping as non-income items you can deduct, but Schedule C instructions still do not say clearly whether fees reduce line 1. Report gross receipts on line 1 and claim fees as expenses unless the final instructions say otherwise.
Part II: Expenses
Expenses must be ordinary (common in your industry) and necessary (helpful and appropriate). Typical lines include:
Advertising, commissions and contract labour
Insurance, legal and professional fees
Rent, repairs, supplies and utilities
Taxes, travel, meals and wages
Vehicles, depreciation and home office
Business meals are generally 50% deductible.
Depreciation and section 179 go through Form 4562.
The simplified home-office method is $5 per square foot, up to 300 square feet; otherwise use Form 8829.
Separate personal from business use and never claim a cost twice.
Part III: Cost of goods sold
Sellers of products use Part III. COGS equals beginning inventory plus purchases, direct labour, materials and other direct costs, minus ending inventory. Materials that become part of goods sold belong here; general supplies and operating costs belong in Part II. Inventory records must reconcile to your books.
A qualifying small business taxpayer may skip inventory accounting if its method clearly reflects income. The 2026 draft instructions use average gross receipts of $32 million or less over three years.
Parts IV and V: Vehicle and other expenses
Complete Part IV when you claim car and truck costs on line 9 and aren't required to file Form 4562. It asks for in-service date, business, commuting and personal miles, and evidence.
The 2026 standard mileage rate is 72.5 cents for January 1 to June 30 and 76 cents from July 1. The 2025 rate was 70 cents. You may use actual expenses instead.
Part V (line 48) lists eligible expenses that don't fit elsewhere, and the total carries to line 27b. Don't put equipment, personal costs or permanent improvements there.
Net profit or loss and loss limits
Line 28 total expenses, subtracted from gross income, gives tentative profit (line 29). Home-office expense on line 30 then leads to net profit or loss on line 31. Losses may be limited by at-risk rules (Form 6198), passive activity rules (Form 8582) and the excess business loss limit (Form 461).
How Schedule C Income Reaches Form 1040
The Schedule C-to-1040 flow
Line 31 net profit goes to Schedule 1 line 3, then Schedule 1 line 10, then Form 1040 line 8. Confirm line numbers on the final 2026 Schedule 1 and Form 1040; draft versions can change before release.
Keep the documents straight: Form 1040 is the main individual return, Schedule C reports the business, and 1099s report payments you must reconcile.
Self-employment tax and earned income
Net profit generally also goes to Schedule SE, which multiplies positive earnings by 92.35%. The rate is 15.3%, and the Social Security portion applies up to the 2026 wage base of $184,500. Half of the SE tax is deductible on Schedule 1.
Net self-employment earnings count as earned income for EITC purposes, subject to eligibility rules. For IRA purposes, they're reduced by the deductible half of SE tax and certain retirement contributions.
Qualified Business Income deduction
Eligible profit may qualify for a QBI deduction, calculated on Form 8995 or 8995-A rather than Schedule C. It reaches Form 1040 line 13b on the draft.
- 2026 taxable-income thresholds: $403,500 joint, $201,750 other filers
- Above the threshold, specified service businesses generally don't qualify, and wage/property limits apply
- A new $400 minimum deduction applies with at least $1,000 of QBI from businesses where you materially participate
- QBI must be effectively connected with a US trade or business
P&L reconciliation
Your P&L supplies revenue and expense totals, but adjust these items before you transfer figures:
- COGS
- Depreciation
- Personal use
- Meals
- Home office
- Inventory
Estimated tax and cross-border points
Estimated payments are generally due if you expect to owe $1,000 or more after withholding. The 2026 dates are April 15, June 15, September 15, and January 15, 2027. The usual safe harbours are 90% of 2026 tax or 100% of 2025 tax (110% if 2025 AGI exceeded $150,000).
For Australian-based owners:
- Under the US-Australia treaty, business profits are generally taxable only in the enterprise's home state absent a permanent establishment. Article 1(3) preserves US taxing rights over citizens and residents.
- Form 1116 claims a limited foreign tax credit. The 2026 foreign earned income exclusion maximum is $132,900, and it doesn't reduce SE tax.
- A self-employed US citizen living in Australia may be exempt from US Social Security under the totalization agreement; attach the exemption letter.
- Convert foreign amounts to US dollars for the US return, and to AUD for the ATO. An FITO claim above A$1,000 requires an offset-limit calculation.
Final Filing Review, Submission, and When to Get Help
Final checklist
- Correct tax-year form
- Income reconciled across books, bank and 1099s
- Separate Schedule C per business
- COGS and inventory tie to the books
- Receipts and mileage evidence on file
- Personal-use allocations made
- Related forms (4562, 8829, SE, 8995) attached
- Signature or e-file validation complete
Submitting and deadlines
File through approved tax software or by mail with Form 1040. For calendar-year 2026, the filing and payment deadline is April 15, 2027.
Form 4868 extends filing to October 15, 2027, but not payment. US citizens abroad with a foreign tax home generally get an automatic extension to June 15, 2027, though interest still accrues from April 15. Check your state's requirements separately.
When to get help
Professional support is worth it when your return involves:
- Australia–US activity or foreign tax credits
- Entity classification questions
- Multiple businesses, inventory, or large losses
- QBI, contractors, or uncertain deductions
VJM Global is a chartered accountancy firm with teams in India serving Australian and international clients. It supports Form 1040 and 1040-NR preparation, foreign tax credit alignment on Form 1116, and cross-border tax compliance. Pricing depends on entity structure and service scope.
Frequently Asked Questions
Where does Schedule C income go on Form 1040?
Line 31 net profit or loss goes to Schedule 1 line 3, then Form 1040 line 8. It also feeds Schedule SE and the QBI calculation.
How do I get a 1040 Schedule C form?
Download the form and instructions from the IRS Schedule C page or use supported tax software. Select the correct tax year, and check whether the instructions are final.
What are the instructions for filing Schedule C on Form 1040?
Gather records, complete Lines A-J, report income, calculate COGS, enter expenses, and find net profit or loss. Then carry the result to Schedule 1 and Form 1040.
How do I calculate Schedule C gross income?
Start with gross receipts, subtract returns and allowances and COGS, then add qualifying other income. Verify line references on the current form.
What can you claim on Schedule C?
Ordinary and necessary business expenses, COGS, eligible vehicle and home-office costs, professional fees, supplies and advertising. Personal or duplicated expenses are excluded.
Why am I getting the Qualified Business Income (QBI) deduction?
Eligible business income may qualify for a separate deduction of up to 20%, subject to income limits, business type and other rules. Schedule C doesn't calculate the full deduction; Form 8995 or 8995-A does.
