Self-Employed & Freelancer Taxes, Taxes

Q4 Estimated Tax Payment 2026: What the IRS Rules Show About the January Deadline

The Q4 2026 estimated tax deadline is January 15, 2027 — covering four months of income (September–December), not three. Here's what the IRS safe harbor rules show about calculating the payment, the 6-7% daily-compounding penalty for missing it, and the one legal way to skip the January deadline entirely.