Schedule C (Form 1040): Profit or Loss from Business (Sole Proprietorship)

The sheet almost every reader of this site files. Gross receipts at the top, expenses by line in the middle, and one net profit at the bottom that carries to your return and to self-employment tax. Get a cost onto the wrong line and the deduction usually survives; get it onto the wrong schedule and it often does not.

Line by line, and what this site says about each

Every row below that carries an article is a rule read from the IRS page that publishes it. The one row that carries none says why.

Line	What it takes	Read
Part I	Gross receipts and returns	Your books and your 1099s will not match No 1099 arrived. You still owe the tax. The retainer you banked in December is December's income Retainage: earned, not received The 1099 vs the commission cheque
8	Advertising	No article. The instructions set no threshold, allocation rule or exclusion for this line, so there is nothing to explain that the line itself does not say.
9	Car and truck expenses	The mileage log that will not hold up The first year decides whether you ever get a choice Your first drive of the shift is probably not deductible
10	Commissions and fees	The 1099 vs the commission cheque
11	Contract labor	The year you hire a second shooter, you become the one issuing forms The 1099s you should not send
13	Depreciation and section 179	Section 179 cannot take you below zero The camera you also film your family with The $2,500 line that decides your tool deductions
17	Legal and professional services	Only part of your tax preparation fee is deductible. The rest is worth nothing.
18, 22, 25	Office expense, supplies, utilities	The first phone line into your home is never deductible. The rest of the bill can be.
21	Repairs and maintenance	Repair or improvement is decided before you spend
24a	Travel	The 50-mile rule is a myth The extension that taxes your stipends
24b	Deductible meals	80% meals, and the 2290 deadline
26	Wages	You cannot put yourself on the payroll. You can put your 16-year-old on it.
27b	Other expenses (from Part V, line 48)	The $2,500 line that decides your tool deductions The closing gift is capped at $25 per client Your CEUs are deductible. Your degree never was.
30	Expenses for business use of your home	You work at client sites all day. Your home office can still qualify. The hours you count are not the hours the children are there
Part III	Cost of goods sold, carried to line 4	The stock you bought in December is not a December deduction

Everything on this site that lands here

Each article declares the sheet its number ends up on, so this list is the writing itself rather than a summary of it.

Read	Where it lands
The 1099-K threshold you think you know	Part I — Gross receipts
The 1099-NEC has new boxes	Part I — Gross receipts, with tips and overtime carrying to Schedule 1-A
Which 1099 describes your money?	Part I — Gross receipts
$600 or $2,000? Both are right	Part I — Gross receipts
A client held back 24% of your invoice	Part I — Gross receipts, with the 24% withheld claimed on Form 1040
Retainage: earned, not received	Part I — Gross receipts
Two 1099s arrived for the same money	Part I — Gross receipts
The product they sent you for free is income	Part I — Gross receipts
A foreign agency sends no form, and the amount is not in dollars yet	Part I — Gross receipts, translated to dollars
No 1099 arrived. You still owe the tax.	Part I — Gross receipts
Your books and your 1099s will not match	Part I — Gross receipts, and the expenses the gross is reduced by
The 1099 vs the commission cheque	Part I — Gross receipts, with commissions paid out on line 10
The retainer you banked in December is December's income	Part I — Gross receipts
Your first drive of the shift is probably not deductible	Line 9 — Car and truck expenses
The mileage log that will not hold up	Line 9 — Car and truck expenses, with Part IV
The first year decides whether you ever get a choice	Line 9 — Car and truck expenses
The year you hire a second shooter, you become the one issuing forms	Line 11 — Contract labor
The 1099s you should not send	Line 11 — Contract labor
The camera you also film your family with	Line 13 — Depreciation and section 179, via Form 4562
Section 179 cannot take you below zero	Line 13 — Depreciation and section 179, via Form 4562
Only part of your tax preparation fee is deductible. The rest is worth nothing.	Line 17 — Legal and professional services
The first phone line into your home is never deductible. The rest of the bill can be.	Lines 18, 22, 25 — Office expense, supplies, utilities
The extension that taxes your stipends	Line 24a — Travel
The 50-mile rule is a myth	Line 24a — Travel
80% meals, and the 2290 deadline	Line 24b — Deductible meals, with Form 2290 on line 23
You cannot put yourself on the payroll. You can put your 16-year-old on it.	Line 26 — Wages, and nothing for amounts paid to yourself
The closing gift is capped at $25 per client	Line 27b — Other expenses, from Part V line 48
Your CEUs are deductible. Your degree never was.	Line 27b — Other expenses, from Part V line 48
The $2,500 line that decides your tool deductions	Line 27b — Other expenses, from Part V line 48
The hours you count are not the hours the children are there	Line 30 — Expenses for business use of your home, via Form 8829
You work at client sites all day. Your home office can still qualify.	Line 30 — Expenses for business use of your home, via Form 8829
The stock you bought in December is not a December deduction	Part III — Cost of goods sold
You gave the money back. The 1099 was still right.	a business expense on the same schedule the income went on

The official page

Everything here is written from the IRS's own material, and the place to check it is Schedule C on irs.gov. Figures and rules change; the source is what settles them.

This is educational material, not tax advice. Your own situation may turn on facts this page does not know about.