Estimated Taxes

Estimated taxes are how the US tax system collects tax on income that nobody withholds for you. Wages run through payroll, where an employer deducts income tax and remits it on the worker’s behalf. Income such as independent contractor earnings, business profit, interest, dividends, and rent usually arrives with nothing taken out. To keep that income current with the government, the payee makes estimated tax payments directly to the IRS during the year. The IRS describes the system on its Estimated Taxes page.

Pay As You Earn

The core principle is that tax is owed as income is earned, not in a single lump sum after the year ends. The IRS puts it plainly: “Taxes must be paid as you earn or receive income during the year, either through withholding or estimated tax payments.” For a salaried employee, withholding satisfies this automatically. For a self-employed person, estimated tax is the substitute. The IRS also notes that estimated tax covers “not only income tax, but other taxes such as self-employment tax and alternative minimum tax.”

Who Must Pay

According to the IRS, “individuals, including sole proprietors, partners, and S corporation shareholders, generally have to make estimated tax payments if they expect to owe tax of $1,000 or more when their return is filed.” In practice this captures most freelancers, gig workers, and independent contractors who receive payments with no withholding. A person who has both a job and side income can often increase wage withholding on Form W-4 instead of sending separate estimated payments.

How It Works

Individuals generally use Form 1040-ES to figure estimated tax. The form’s worksheet projects the year’s expected income, deductions, and credits to arrive at the tax owed, which is then spread across the year. The IRS states that “the year is divided into four payment periods,” each with its own due date, so estimated tax is paid in four installments. Paying too little can trigger a penalty: the IRS says “you may have to pay a penalty for underpayment of estimated tax” unless you meet one of its safe harbors, such as owing less than the threshold after withholding and credits.

Why It Matters for Contractors

A US business paying an independent contractor does not withhold income tax from those payments. The contractor receives the gross amount, often reported later on a Form 1099-NEC, and is responsible for their own income tax and self-employment tax through estimated payments. This is the structural difference from payroll tax on wages, where the employer handles deduction and remittance. Missing a valid taxpayer ID on a Form W-9 can also expose those payments to backup withholding, a separate mechanism from estimated tax.

Omnivoo Contract Management collects each US contractor’s W-9, tracks payments through the year, and produces the 1099-NEC records that let the contractor reconcile their estimated tax at filing.