Self-employed workers, freelancers, and small-business owners in Brownsville and across the Rio Grande Valley often receive income without payroll withholding. The Internal Revenue Service (IRS) explains that federal tax is still due on a pay-as-you-go basis, often through quarterly estimated tax payments. This article summarizes IRS estimated-tax rules for individuals, the 2026 Form 1040-ES due dates, common ways to pay, and where Publication 505 fits. Sources were checked on October 16, 2026. It is general information, not advice about any specific person's tax situation.
Why estimated taxes matter for self-employed people
The IRS states that taxes must be paid as you earn or receive income during the year, either through withholding or estimated tax payments. If the amount withheld from salary or pension is not enough, or if you receive income such as interest, dividends, self-employment income, capital gains, prizes, or awards, you may have to make estimated tax payments. If you are in business for yourself, you generally need to make estimated tax payments. Estimated tax is used to pay not only income tax, but other taxes such as self-employment tax and alternative minimum tax (IRS: Estimated taxes).
Who generally must pay estimated tax
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 (IRS: Estimated taxes; Publication 505 (2026), Tax Withholding and Estimated Tax).
The IRS also describes when you do not have to pay estimated tax for the current year if you had no tax liability for the prior year, you were a U.S. citizen or resident alien for the whole year, and your prior tax year covered 12 months (IRS: Estimated taxes).
If you receive salaries and wages, the IRS notes that you can avoid estimated tax by asking your employer to withhold more tax using Form W-4 (IRS: Estimated taxes).
Form 1040-ES basics
Use Form 1040-ES, Estimated Tax for Individuals to figure and pay your estimated tax. The IRS states that estimated tax is the method used to pay tax on income that is not subject to withholding—for example, earnings from self-employment, interest, dividends, rents, and similar items (About Form 1040-ES).
To figure estimated tax, the IRS states that you must estimate adjusted gross income, taxable income, taxes, deductions, and credits for the year. Prior-year figures and the Form 1040-ES worksheet are a common starting point; refigure a later quarter if earnings run higher or lower than expected (IRS: Estimated taxes). Publication 505 adds detail on installments and special rules for farmers, fishermen, and higher-income taxpayers (Publication 505).
When to pay: the four IRS payment periods for 2026
For estimated tax purposes, the year is divided into four payment periods. Each period has a specific payment due date. If you do not pay enough tax by the due date of each payment period, you may be charged a penalty even if you are due a refund when you file (IRS FAQ: When are quarterly estimated tax payments due?).
The IRS payment-period table (checked October 16, 2026) is:
- January 1–March 31 — due April 15
- April 1–May 31 — due June 15
- June 1–August 31 — due September 15
- September 1–December 31 — due January 15 of the following year
For calendar-year 2026, Form 1040-ES (2026) lists the four payment due dates as April 15, 2026; June 15, 2026; September 15, 2026; and January 15, 2027. The form states that you do not have to make the January 15, 2027 payment if you file your 2026 tax return by February 1, 2027, and pay the entire balance due with your return (Form 1040-ES PDF).
If a due date falls on a Saturday, Sunday, or legal holiday, the IRS states that the payment will be on time if you make it on the next day that is not a Saturday, Sunday, or legal holiday (IRS FAQ: When are quarterly estimated tax payments due?; IRS: Estimated taxes). If a payment is mailed, the date of the U.S. postmark is the date of payment (IRS: Estimated taxes).
How to pay estimated taxes
The IRS states that you may send estimated tax payments with Form 1040-ES by mail, or you can pay online, by phone, or from your mobile device using the IRS app. You can also make estimated tax payments through your online account, where you can see your payment history and other tax records (IRS: Estimated taxes; IRS Payments).
The IRS payments hub lists bank account payments through an IRS Individual Account or Direct Pay, plus debit or credit card (fees apply), digital wallet, same-day wire, check or money order, and cash at participating locations (IRS Payments). You may also pay more often than quarterly as long as you have paid enough by the end of the quarter (IRS: Estimated taxes).
Underpayment penalty — how the IRS describes the safe harbors
The IRS states that if you did not pay enough tax throughout the year, either through withholding or by making estimated tax payments, you may have to pay a penalty for underpayment of estimated tax. Generally, most taxpayers will avoid this penalty if they owe less than $1,000 in tax after subtracting withholdings and credits, or if they paid at least 90% of the tax for the current year, or 100% of the tax shown on the return for the prior year, whichever is smaller. There are special rules for farmers, fishermen, and certain higher-income taxpayers (IRS: Estimated taxes; Publication 505).
If income is uneven during the year, the IRS notes that annualizing income on Form 2210 may avoid or lower the penalty (IRS: Estimated taxes).
Texas note: no state personal income tax
Federal estimated tax rules apply nationwide. Separately, the Texas Comptroller of Public Accounts states that Texas has no state income tax (Texas Comptroller: Texas is open for small business). That fact does not change federal estimated-tax requirements described by the IRS.
Step by step: a practical review for RGV self-employed workers
Step 1: Confirm whether you may need estimated payments
Compare expected year-end tax (including self-employment tax) to withholding. The IRS generally points to the $1,000 threshold and the Form 1040-ES worksheet (IRS: Estimated taxes).
Step 2: Use Form 1040-ES and last year's return as a starting point
Download current Form 1040-ES, complete the worksheet, and adjust prior-year figures for changes in your situation and the tax law (IRS: Estimated taxes; Publication 505).
Step 3: Mark the four due dates on your calendar
For 2026 calendar-year taxpayers, the Form 1040-ES due dates are April 15, 2026; June 15, 2026; September 15, 2026; and January 15, 2027 (with the January exception described above) (Form 1040-ES PDF).
Step 4: Choose a payment method and keep records
Pay through your IRS online account, Direct Pay, mail with a Form 1040-ES voucher, or another method listed on IRS.gov/payments. Save confirmation numbers or canceled checks.
Step 5: Recalculate when income changes
If earnings run higher or lower than expected, complete another Form 1040-ES worksheet and adjust the next quarter's payment (IRS: Estimated taxes).
Step 6: Review Publication 505 for special situations
Farmers, fishermen, higher-income taxpayers, and people with uneven income should review Publication 505.
Frequently asked questions
Do self-employed people in South Texas always have to pay estimated tax?
Not automatically. The IRS generally requires estimated payments when you expect to owe $1,000 or more when you file (IRS: Estimated taxes).
What are the 2026 Form 1040-ES due dates?
April 15, 2026; June 15, 2026; September 15, 2026; and January 15, 2027. You may skip the January 15, 2027 payment if you file your 2026 return by February 1, 2027, and pay the full balance due (Form 1040-ES PDF).
Can I pay more often than once per quarter?
Yes. The IRS states that you may pay weekly, bi-weekly, monthly, or on another schedule as long as you have paid enough by the end of the quarter (IRS: Estimated taxes).
Does Texas state income tax also require quarterly estimates?
The Texas Comptroller states that Texas has no state income tax (Texas Comptroller small-business page). Federal estimated tax is separate and still applies under IRS rules.
Where can I read the official rules?
Start with Estimated taxes, About Form 1040-ES, Form 1040-ES (PDF), Publication 505, and the estimated-tax FAQ on due dates.
Questions in the Rio Grande Valley
Garduño Tax & Associates works with individuals, families, and small businesses in Brownsville and South Texas. If you need help organizing self-employment records or reviewing Form 1040-ES worksheets and due dates, you can contact the office to talk through the documents involved.
This article is general information, not tax advice. Reading it or contacting the office does not create a client relationship.