What Form Do Contractors Fill Out? W-9, 1099-NEC & Schedule C

Independent contractors fill out Form W-9 for each new client, then file Schedule C, Schedule SE, and Form 1040-ES alongside their annual Form 1040. Together, those forms cover what independent contractors fill out to share their taxpayer information, report business income and expenses, calculate self-employment tax, and pay the IRS in quarterly installments. Federal filing kicks in once net self-employment earnings pass $400 for the year.¹

Form W-9 Goes to the Client

Form W-9 (Request for Taxpayer Identification Number and Certification) is usually the first form a contractor sees. A client that hires you needs your taxpayer information so it can report your payments to the IRS at year-end. You fill out the W-9 and hand it back to the client; it never gets sent to the IRS.²

The form asks for a few things:

Your legal name as it appears on your tax return. A business or trade name goes on the second line.²
Your federal tax classification: individual/sole proprietor, C corporation, S corporation, partnership, LLC, or trust/estate.²
Your Taxpayer Identification Number, which for most individual contractors is a Social Security Number, or an Employer Identification Number if you have one. The TIN has to match the name on line 1.²
Your signature certifying under penalty of perjury that the TIN is correct and you’re not subject to backup withholding.

Skip the W-9 or give the wrong TIN and the client is required to withhold 24% of your payments as backup withholding and send it to the IRS. You would recover it later as a credit on your annual return.³

Form 1099-NEC Comes to You

Form 1099-NEC (Nonemployee Compensation) is not something a contractor fills out. It’s a statement the client sends to you and to the IRS reporting what it paid you for the year.⁴ Even if a client pays you too little to trigger a 1099-NEC, you still have to report the income. Keep your own records of every payment, because the total on your return should reflect what you were actually paid, not just what shows up on 1099s.

Schedule C Reports Your Business Profit

Schedule C (Profit or Loss From Business) is where you report gross receipts, subtract deductible expenses, and land on a net profit or loss. It attaches to your Form 1040, and the bottom-line number flows into both your income tax and your self-employment tax.⁵

Start with the total of everything clients paid you, then subtract ordinary and necessary business expenses. Common ones include office supplies, advertising, professional fees like an accountant, and business travel costs such as lodging and transportation.⁵ Organized records through the year make this much easier and help you claim everything you’re entitled to.

Home Office

If you use part of your home regularly and exclusively for business, you can deduct a portion of your housing costs. The simplified method allows $5 per square foot of your dedicated workspace, capped at 300 square feet and $1,500 total. The regular method requires tracking actual rent, utilities, and insurance, then applying the business-use percentage of your home.⁶

Health Insurance

Self-employed contractors who pay for their own health coverage can deduct 100% of premiums for themselves, a spouse, dependents, and children under age 27. The deduction can’t exceed your net self-employment income, and you can’t claim it for any month you were eligible for an employer-subsidized plan, including through a spouse. You calculate this on Form 7206 and report it on Schedule 1 of Form 1040, not on Schedule C.⁷

Schedule SE Calculates Self-Employment Tax

Schedule SE figures the Social Security and Medicare taxes you owe on net self-employment income. Employees split these with their employer; contractors pay both halves. The combined rate is 15.3%, which is 12.4% for Social Security plus 2.9% for Medicare.⁸

For 2026, the 12.4% Social Security portion applies to the first $184,500 of net self-employment earnings. Anything above that is still subject to the 2.9% Medicare tax, which has no cap.⁹ Net earnings above $200,000 (single) or $250,000 (married filing jointly) pick up an additional 0.9% Medicare tax on the amount over that threshold.

One partial offset: you can deduct half of your self-employment tax when calculating adjusted gross income. That deduction goes on Schedule 1 of Form 1040 and reduces your overall taxable income.¹⁰

Form 1040-ES for Quarterly Estimated Payments

Nobody withholds taxes from your contractor payments, so you generally pay estimated taxes four times a year using Form 1040-ES. Payments are required if you expect to owe $1,000 or more in tax for the year after subtracting withholding and refundable credits.¹¹

The 2026 quarterly deadlines for individual taxpayers:

First quarter: April 15, 2026
Second quarter: June 15, 2026
Third quarter: September 15, 2026
Fourth quarter: January 15, 2027

You can skip the January 15 payment if you file your 2026 return and pay any remaining balance by February 1, 2027.¹¹

Form 1040-ES includes a worksheet that walks you through estimating annual tax from expected income, deductions, and credits. Your prior return is a useful starting point. Divide the annual estimate into four roughly equal installments and adjust as income shifts.

Safe Harbors

The IRS won’t charge an underpayment penalty if your estimated payments and withholding cover at least the smaller of:

90% of your current year’s tax liability, or
100% of last year’s tax liability, or 110% if your prior-year adjusted gross income exceeded $150,000 ($75,000 if married filing separately).¹²

Hitting one of these protects you even if your actual tax comes in higher. Contractors with uneven income often prefer the prior-year safe harbor because the target is fixed.

Qualified Business Income Deduction

Most sole proprietors, partners, and S corporation shareholders can deduct up to 20% of their qualified business income, cutting their taxable income without cutting their self-employment tax. The deduction was originally set to expire after 2025 but was made permanent by the One Big Beautiful Bill Act signed in July 2025.¹³

The deduction is limited to the lesser of 20% of qualified business income or 20% of taxable income minus net capital gains. Higher-income taxpayers face additional limits tied to wages paid and business property owned, but most contractors under the upper income thresholds can claim the full 20%. Income earned through a C corporation or as an employee does not qualify.¹³

State Forms Are Separate

Federal forms don’t cover state duties. Most states impose their own income tax on self-employment earnings, with rates ranging from 0% in states without an income tax to over 13% in the highest-tax states. Some states require quarterly estimated payments that mirror the federal schedule; others use different deadlines or thresholds. Check with your state’s tax agency for filing rules and any business registration requirements, which typically carry fees ranging from roughly $50 to several hundred dollars depending on location and business type.

1
Office of the Law Revision Counsel. 26 USC 1402 – Definitions
2
Internal Revenue Service. Form W-9, Request for Taxpayer Identification Number and Certification
3
Office of the Law Revision Counsel. 26 USC 3406 – Backup Withholding
4
Internal Revenue Service. 2026 Publication 1099, General Instructions for Certain Information Returns
5
Internal Revenue Service. 2025 Instructions for Schedule C, Form 1040
6
Internal Revenue Service. Simplified Option for Home Office Deduction
7
Internal Revenue Service. About Form 7206, Self-Employed Health Insurance Deduction
8
Internal Revenue Service. Topic No. 554, Self-Employment Tax
9
Social Security Administration. Contribution and Benefit Base
10
Office of the Law Revision Counsel. 26 USC 164 – Taxes
11
Internal Revenue Service. 2026 Form 1040-ES, Estimated Tax for Individuals
12
Internal Revenue Service. Estimated Tax
13
Internal Revenue Service. Qualified Business Income Deduction