Not tax advice. Computation tools only. Have a professional review before filing.

tax-calendar/us/us-q4-estimated-tax-january-15

USSelf-employedSmall business

Q4 Estimated Tax (Form 1040-ES)

Final quarterly estimated tax payment for tax year 2025. Covers September through December 2025 earnings.

Filing deadline

January 15, 2026

Country: United States
Tax year: 2025
Official: Tax authority

What is this deadline?

The Q4 estimated payment for the prior year (tax year 2025). Last chance to top up before filing the annual return.

Key dates

Due: January 15, 2026

What people miss

Paying Q4 at the safe-harbor level (100%/110% of prior-year tax) is the cleanest way to avoid underpayment penalties even if you massively over-earned in Q4. Don't overpay current-year actual if the safe harbor already covers you.

Prepare this return with open-source skills

These skills are in the OpenAccountants repo. Clone them into Claude, Cursor, or any AI agent and they handle the computation.

us-quarterly-estimated-tax.mdUS

Use this skill whenever asked about US federal quarterly estimated income tax payments for sole proprietors and single-member LLCs. Trigger on phrases like "1040-ES", "estimated tax", "quarterly tax", "safe harbor", "underpayment penalty", "Form 2210", "annualized income", or any question about federal estimated tax requirements. Covers the $1,000 threshold, 100%/110% prior-year safe harbor, 90% current-year method, quarterly due dates, annualized income instalment method, Form 2210 penalty computation, and withholding strategies. MUST be loaded alongside us-tax-workflow-base v0.1+. Federal only.

This page is informational only and not tax advice. Verify dates and requirements against the official tax authority before filing.

Q1 Estimated Tax (Form 1040-ES)

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