Who usually checks this
Sole proprietors, independent contractors, partners, S corporation shareholders, and employees with too little withholding commonly use this schedule.
1099 tax deadline guide
2026 estimated tax due dates
Freelancers and other taxpayers who do not have enough tax withheld may need to make estimated tax payments. These are the standard 2026 calendar-year due dates to check before using the 1099 tax calculator.
Use this as a planning checklist only. IRS deadlines can be affected by weekends, legal holidays, fiscal-year filing, disaster relief, deposit rules, and entity-specific facts.
| 2026 income period | Payment due date | Planning note |
|---|---|---|
| Jan. 1 - Mar. 31 | April 15, 2026 | First estimated tax payment for 2026 income. |
| Apr. 1 - May 31 | June 15, 2026 | Second estimated tax payment for 2026 income. |
| June 1 - Aug. 31 | September 15, 2026 | Third estimated tax payment for 2026 income. |
| Sept. 1 - Dec. 31 | January 15, 2027 | Fourth estimated tax payment for 2026 income. |
Use with the calculator
Run the 1099 calculator, divide the estimated annual reserve into quarterly payments, then compare each date against the IRS calendar.
Source check
The IRS estimated tax FAQ lists the standard payment periods and due dates. Publication 509 is the broader IRS tax calendar.
Sources: IRS estimated tax FAQ, IRS Publication 509, and IRS Publication 505. Last generated 2026-08-16.