IRS Schedule C Line 31: How To Figure Out and Use Your Net Profit (or Loss)

What Line 31 Actually Is and Why It Matters

Line 31 on IRS Form 1040 Schedule C is where you report your net profit or loss from your business.
This is the amount the IRS uses to figure both your income tax and, if you’re self‑employed, your self‑employment tax on Schedule SE.

Line 31 is not just your sales or deposits; it is your gross income minus all allowed business expenses on Schedule C.
If Line 31 is wrong, your tax bill, your eligibility for some credits, and even things like mortgage applications or child support calculations can be off.

Key terms to know:

• Gross income — Your total business income (sales, fees, commissions) before any expenses.
• Net profit (or loss) — What’s left after subtracting all allowed business expenses; this is what goes on Line 31.
• Schedule C — The IRS form used by sole proprietors and single‑member LLCs to report business income and expenses.
• Schedule SE — The IRS form that uses your Schedule C Line 31 amount to calculate self‑employment tax.

Where Line 31 Goes in the System and Who Handles Questions

Schedule C is processed by the Internal Revenue Service (IRS) and feeds directly into Form 1040 and often Schedule SE.
If you file electronically, tax software typically takes your Line 31 net profit and automatically carries it over to the right line on Form 1040 and into Schedule SE if needed.

There are two main official system touchpoints for questions or corrections related to Line 31:

• IRS taxpayer assistance system — This includes the national IRS phone line and local Taxpayer Assistance Centers (TACs). You can search for “IRS Taxpayer Assistance Center” plus your city or ZIP to find an office; these are federal offices and will show up with .gov in the web address.
• IRS‑approved Volunteer Income Tax Assistance (VITA) or Tax Counseling for the Elderly (TCE) programs — These are typically run at community centers, libraries, and nonprofits but are overseen by the IRS. They often help self‑employed people with basic Schedule C issues, especially if income is modest.

Because tax rules can change and some details differ by situation (and, for state tax purposes, by location), you should confirm any questions that affect big dollar amounts or unusual expenses using an official source, like the IRS phone line or an enrolled agent/CPA.

If you look for help online, use only government or well‑known nonprofit sites and look for addresses ending in .gov for anything that asks for personal information to reduce the risk of scams.

How To Calculate Line 31 in Practice

To fill in Line 31 correctly, you usually walk down Schedule C in this order: income at the top, expenses in the middle, and then the net amount on Lines 29–31 at the bottom.
Here’s how that usually plays out in real life.

Documents you’ll typically need:

• Bank statements and payment platform reports (e.g., from PayPal, Stripe, Square, Etsy) to tally business income.
• Receipts or accounting records for business expenses, such as supplies, advertising, mileage logs, or software subscriptions.
• Prior‑year tax return and Schedule C, so you can keep categories consistent and check for missing regular expenses like insurance or licenses.

Step‑by‑step: From income and expenses to Line 31

1. Total your business income
   Add up all your business income for the year: customer payments, platform payouts, checks, cash, and 1099‑NEC/1099‑K amounts.
   On Schedule C, this is typically entered on Line 1 (gross receipts or sales) and then adjusted by returns/allowances and other income to reach Line 7 (gross income).

2. List and categorize your expenses
   Go through your bank/credit card statements and receipts for the year.
   Match each expense to one of the categories on Lines 8–27 of Schedule C (e.g., advertising, car and truck expenses, office expense, supplies, utilities, etc.), or use Line 27a “Other expenses” if it doesn’t clearly fit a listed category.

3. Check for special categories that affect Line 31
   Some expenses (like home office, certain vehicle expenses, or depreciation) may require separate worksheets or Form 4562 before you plug a final number into Schedule C.
   Tax software often walks you through these; if doing it on paper, read the Schedule C instructions for any expense type you’re unsure about, because incorrect calculations here directly change Line 31.

4. Calculate total expenses and tentative profit
   Add up all expenses on Lines 8–27a, then enter that total on Line 28 (Total expenses).
   Subtract Line 28 from Line 7 to get Line 29 (Tentative profit or loss).

5. Adjust for any business‑use‑of‑home deduction
   If you qualify for a home office deduction, this is entered on Line 30 (either using the simplified method or the long‑form calculation).
   Subtract Line 30 from Line 29 to get Line 31: Net profit or (loss) — this is the key number that flows to your Form 1040 and usually to Schedule SE.

6. Copy Line 31 to the right place on Form 1040
   If Line 31 is a profit, tax software (or the Schedule C instructions) will tell you where to report it on Form 1040 (the specific line number can change by year).
   If Line 31 shows a loss, you may need to check whether you are at‑risk for that amount or if the loss is limited by passive activity rules, which is where IRS publications or a tax professional become especially helpful.

Concrete action you can take today:
Pull your latest 12 months of bank and payment app statements and start listing every income and expense item that is clearly business‑related under the categories that match Schedule C lines.
Once this list is ready, it usually takes far less time for software, a VITA/TCE volunteer, or a tax pro to help you compute Line 31 accurately.

What happens after you complete Line 31

Once Line 31 is calculated and your tax return is filed:

• The IRS computer system uses that Line 31 amount to figure your adjusted gross income (AGI) and, through Schedule SE, your self‑employment tax.
• If you’re due a refund or owe money, the IRS issues a notice or processes any payment you send; you typically receive either a refund deposit/check or a balance due notice.
• If something on Schedule C (including Line 31) doesn’t match income reports they received (like 1099‑K or 1099‑NEC forms), the IRS may later send you a notice proposing a change, asking you to verify income or expenses.

Real‑World Friction to Watch For

Real‑world friction to watch for
A very common snag is missing or mixed personal/business records, which makes it hard to justify the expenses that reduce your Line 31 profit. If you can’t show clear proof for major expenses during an IRS review, the IRS may remove those deductions, increase your Line 31 profit, and bill you for extra tax plus interest, so it’s safer to be conservative with expenses you can’t document well.

How To Get Official Help With Line 31 Issues

If you’re unsure whether you’ve calculated Line 31 correctly, or you get an IRS notice about it, there are official channels you can use; you should not send personal data through random websites or social media.

1. Contact the IRS directly

You can:

• Call the IRS taxpayer assistance line — Use the main IRS phone number listed on the official IRS site; have your Social Security number/ITIN, prior‑year return, and current Schedule C handy.
  A simple script: “I’m self‑employed and have a question about how my Schedule C Line 31 net profit should be reported on my Form 1040 and Schedule SE.”
• Visit an IRS Taxpayer Assistance Center (TAC) — Search for “IRS Taxpayer Assistance Center” and your city to find the nearest one. These offices generally require an appointment; when you call the number listed on the .gov site, choose the option for in‑person help.

What to expect next: the IRS representative usually cannot do full bookkeeping for you, but they can explain how Line 31 flows to Form 1040, what forms are required, and how to respond to any notice you received.

2. Use IRS‑linked free tax help programs

If your income is within certain limits or you’re age 60+, you may qualify for free help:

• Search for “VITA site near me” or “TCE AARP Tax‑Aide” to find local, IRS‑partnered programs.
• These sites often file returns electronically and can help you input Schedule C income and expenses properly.

When you go, bring:

• All Forms 1099‑NEC, 1099‑K, and 1099‑MISC that relate to your business.
• Printed or digital income/expense summaries (for example, a spreadsheet or accounting software report).
• Photo ID and Social Security card or ITIN letter for you and anyone else on your return.

What happens after: they typically e‑file your return with the IRS and give you a copy of the return showing your Line 31 amount. Any refund or tax bill is then handled directly by the IRS, not by the VITA/TCE site.

3. When to consider a paid tax professional

If your Line 31 calculation involves:

• Multiple businesses,
• Inventory and cost of goods sold,
• Large equipment purchases or depreciation,
• Home office and complex vehicle use, or
• Past‑due returns or IRS notices,

it’s often worth contacting a licensed tax professional—a CPA, enrolled agent (EA), or tax attorney.
Search for professionals using your state’s CPA society, the IRS directory of credentialed preparers, or other reputable directories, and verify their status before you share personal documents.

Simple Step Sequence You Can Follow Right Now

1. Gather your business records for the year
   Collect bank statements, app payout reports, and receipts tied to your business.
   This is the base for both your income total and the expenses that determine Line 31.

2. Match your records to Schedule C categories
   Get a blank Schedule C (from the IRS site or tax software) and write down your income on Line 1 and classify each expense under the closest matching line (e.g., Line 18 for office expense, Line 20b for utilities).
   For any expense that doesn’t clearly fit a listed category, set it aside for possible entry on Line 27a “Other expenses” and be prepared to describe it.

3. Compute your tentative Line 31 (even if you plan to get help)
   Add up your income, subtract expenses, and write down the resulting net profit or loss.
   This doesn’t have to be final; the point is to know roughly what number you’re taking to a VITA site, IRS TAC, or tax professional, so they can check or refine it.

4. Contact an official help source if you’re unsure or have a notice
   If anything is unclear, call the IRS assistance line or book a VITA/TCE appointment, explaining that your question is about Schedule C Line 31.
   Expect them to ask for your prior‑year return, identification, and detailed income/expense information, and understand they will not guarantee a certain refund or outcome.

5. Respond promptly to any IRS notice about Line 31
   If you receive a letter saying your business income or expenses don’t match what they have on file, follow the instructions on that notice—usually mailing or uploading copies of records by a specific deadline.
   If you ignore the notice, the IRS will typically adjust your return in their favor (increasing tax due) and may start collection processes, so responding on time is critical.

Common snags (and quick fixes)

• Problem: No clear separation between personal and business expenses.
  Quick fix: Go through each statement line and mark only clearly business‑related charges; if in doubt and you lack documentation, leave it out or ask a professional before claiming it.

• Problem: You received 1099‑K or 1099‑NEC forms that don’t match your own income totals.
  Quick fix: Reconcile each 1099 form to your records; if you truly believe it’s wrong, contact the payer for a corrected form before filing, or include an explanation when you respond to an IRS notice.

• Problem: You find out late that your return had the wrong Line 31.
  Quick fix: Use Form 1040‑X (Amended U.S. Individual Income Tax Return) to correct the return; attach a corrected Schedule C and any supporting documents, and understand that any extra tax due may also come with interest.

Because Line 31 changes how much tax you pay, be cautious about any person or website promising big refunds based on “creative” business deductions or asking you to send them copies of IDs or tax documents outside secure, recognized channels.
Search for your state’s official attorney general consumer protection office or your state CPA licensing board if you suspect a preparer or advisor is running a scam or misusing your information.