If you earn money outside a regular paycheck, here is how to report cash income to the IRS: add up everything you received during the year, list it as gross receipts on Schedule C, subtract your business expenses to get a net profit, and carry that number to Schedule 1 of your Form 1040. You’ll also owe self-employment tax on the net profit through Schedule SE, and you’re expected to pay both income tax and SE tax in four estimated installments during the year rather than in a lump sum at filing.1Internal Revenue Service. About Schedule C (Form 1040), Profit or Loss from Business (Sole Proprietorship)
What Counts as Cash Income
Cash income is not just paper bills. The IRS treats any payment for work, services, or goods as taxable unless a specific provision excludes it, regardless of how the money reached you.2Internal Revenue Service. Taxable Income That includes gig work, freelancing, side jobs, handmade goods, tips collected directly from customers, and transfers through PayPal, Venmo, Zelle, or Cash App.
Barter counts too. If you build a website for a plumber who fixes your pipes in return, both of you owe tax on the fair market value of what you received.3Internal Revenue Service. Bartering and Trading – Each Transaction Is Taxable to Both Parties Cryptocurrency received as payment works the same way: the fair market value on the day you receive it is ordinary income, reported on Schedule C when it comes from freelancing or self-employment.4Internal Revenue Service. Frequently Asked Questions on Virtual Currency Transactions
One point worth clearing up before you file. Payment apps are only required to send you a Form 1099-K if your payments for goods or services exceed $20,000 and involve more than 200 transactions in a calendar year; the One, Big, Beautiful Bill restored that threshold after Congress had briefly dropped it to $600.5Internal Revenue Service. IRS Issues FAQs on Form 1099-K Threshold Under the One, Big, Beautiful Bill Falling below that threshold does not make the income tax-free. You owe tax on every dollar of profit whether or not any platform reports it.
Filling Out Schedule C
Schedule C is where sole proprietors and most self-employed people report cash income. You list total gross receipts at the top, subtract business expenses in Part II, and arrive at a net profit or loss on line 31.1Internal Revenue Service. About Schedule C (Form 1040), Profit or Loss from Business (Sole Proprietorship)
Gross receipts means the total you collected before deducting anything. That’s the number that has to appear on your return even after your expenses knock the taxable portion down. Bank deposits are visible to the IRS, so a gross figure that doesn’t match your reported income is exactly the kind of gap an auditor will look at.
Your Schedule C net profit flows to Schedule 1, line 3, and the Schedule 1 total moves to line 8 of your Form 1040, feeding into your adjusted gross income.6Internal Revenue Service. 2025 Schedule 1 (Form 1040) If your net self-employment earnings are $400 or more, you also file Schedule SE.7Internal Revenue Service. Instructions for Schedule SE (Form 1040)
Deductions That Reduce What You Owe
Every legitimate expense you deduct on Schedule C lowers both your income tax and your self-employment tax. The standard is any cost that is “ordinary and necessary” for your line of work.8Internal Revenue Service. Instructions for Schedule C (Form 1040) Common ones for cash-based work:
- Vehicle expenses, deducted either as actual costs or at the 2026 standard mileage rate of 72.5 cents per mile, backed by a log with dates, destinations, and business purpose.9Internal Revenue Service. IRS Sets 2026 Business Standard Mileage Rate at 72.5 Cents per Mile
- Supplies and materials consumed in your work.
- Business insurance premiums.
- Payments to subcontractors or helpers you don’t treat as employees.
- Advertising, website costs, and business cards.
- Tax preparation for your business return and business-related legal fees.
- Business meals at 50% of cost.
- A home office used regularly and exclusively for business, either at a proportional share of household costs or the simplified rate of $5 per square foot up to 300 square feet, a $1,500 cap.10Internal Revenue Service. Simplified Option for Home Office Deduction
Track expenses as they happen. Reconstructing a year at tax time almost always means missing deductions you earned.
Self-Employment Tax
Cash earners pay both halves of Social Security and Medicare, which a W-2 employee splits with an employer. That combined obligation is self-employment tax, and it’s separate from income tax.11Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes)
The rate is 15.3%: 12.4% for Social Security and 2.9% for Medicare. Schedule SE first multiplies your net earnings by 92.35% before applying the rate, which mirrors the break W-2 workers get on the employer half.12Internal Revenue Service. Topic No. 554, Self-Employment Tax A $50,000 net profit on Schedule C produces SE tax on roughly $46,175.
The 12.4% Social Security portion applies only to the first $184,500 of combined wages and self-employment earnings in 2026.13Social Security Administration. Contribution and Benefit Base The 2.9% Medicare portion has no cap. An additional 0.9% Medicare tax applies to earnings above $200,000, or $250,000 if you’re married filing jointly.11Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes)
You can deduct the employer-equivalent portion of your SE tax (roughly half) as an above-the-line adjustment on Form 1040. That reduces your AGI and your income tax, though it does not reduce the SE tax itself.11Internal Revenue Service. Self-Employment Tax (Social Security and Medicare Taxes)
Quarterly Estimated Payments
Cash income has no automatic withholding. If you expect to owe $1,000 or more at filing, the IRS expects you to pay in four installments during the year.14Internal Revenue Service. Estimated Taxes The 2026 deadlines:
- April 15, covering January through March
- June 15, covering April and May
- September 15, covering June through August
- January 15, 2027, covering September through December
When a deadline falls on a weekend or holiday, the payment is due the next business day.15Internal Revenue Service. When Are Quarterly Estimated Tax Payments Due? Each installment should cover roughly a quarter of your projected annual tax, income tax and SE tax combined. Form 1040-ES has a worksheet for the calculation, and most people send payments through IRS Direct Pay or EFTPS.
Miss or underpay and you face an underpayment penalty based on the shortfall, the length of the underpayment, and IRS quarterly interest rates. You avoid the penalty if your total tax due at filing is under $1,000, or if you paid at least 90% of the current year’s tax or 100% of the prior year’s tax, whichever is less. If your prior-year AGI exceeded $150,000, the safe harbor rises to 110% of the prior year’s tax.16Internal Revenue Service. Underpayment of Estimated Tax by Individuals Penalty
If You Earn Tips as a W-2 Employee
The Schedule C route above is for self-employed cash earners. If you’re a restaurant server, bartender, or hairdresser earning tips as an employee, you report those tips to your employer instead, and the employer includes them on your W-2 and withholds payroll tax.17Internal Revenue Service. Tip Recordkeeping and Reporting
Any written statement with your name, Social Security number, employer details, reporting period, and total tips works; Form 4070 is one template. Reports are due by the 10th of the month following the month you received the tips. You don’t have to report months where your tips from a single employer were less than $20, but the income is still taxable when you file.18Internal Revenue Service. Form 4070 – Employee’s Report of Tips to Employer Keep a daily record.
Records to Keep
Cash doesn’t leave the paper trail that card sales and direct deposits do, so your own records are the only proof of what you reported.19Internal Revenue Service. Topic No. 305, Recordkeeping At a minimum:
- An income log with date, client, description, and amount for every payment
- Copies of every invoice you issue
- Deposit slips showing cash going into your business account
- Receipts for every business purchase, with vendor, amount, and purpose noted
- A mileage log with date, destination, miles, and business reason for each trip
Use a dedicated bank account for the business. Mixing personal and business transactions gives an auditor reason to question every deposit. Electronic records are fine if they’re legible and reproducible.
Keep records at least three years from the filing date or the due date, whichever is later.20Internal Revenue Service. How Long Should I Keep Records? If you omit more than 25% of the gross income shown on your return, the IRS gets six years to assess.21Office of the Law Revision Counsel. 26 USC 6501 – Limitations on Assessment and Collection Six years is the safer practical minimum.
What Happens If You Don’t Report
Bank deposits, payment-app records, and audits of your clients all surface unreported cash. Three civil penalties hit most often:
- Failure to file: 5% of the unpaid tax per month if you owe and don’t file by the deadline, capped at 25%.22Internal Revenue Service. Failure to File Penalty
- Failure to pay: 0.5% of the unpaid tax per month if you file but don’t pay in full, also capped at 25%.23Internal Revenue Service. Failure to Pay Penalty
- Accuracy-related penalty: an extra 20% of the underpayment for negligence or a substantial understatement, defined as the greater of 10% of the tax due or $5,000.24Office of the Law Revision Counsel. 26 USC 6662 – Imposition of Accuracy-Related Penalty on Underpayments
Interest compounds daily on the unpaid balance from the original due date, running on top of the penalties. Willful evasion is a separate matter: federal tax evasion carries a maximum fine of $100,000 and up to five years in prison.25Office of the Law Revision Counsel. 26 USC 7201 – Attempt to Evade or Defeat Tax Filing an honest return, even if the numbers are smaller than you’d like, is the better outcome.
State and Local Obligations
Federal tax isn’t the whole bill. Most states tax self-employment earnings, with filing thresholds that vary; a handful of states have no individual income tax at all. Check your state’s department of revenue for the specific rules that apply. Some cities and counties also require a business license or permit for home-based work, and fees run from under $50 to several hundred dollars depending on location and industry. Operating without one where it’s required can cost more than the license itself.