What changed — and where to verify it.

Practical guide: review 2026 estimated tax before September 15

The next regular 2026 estimated-tax payment date for calendar-year individuals is September 15. It covers the June 1–August 31 payment period and may matter when withholding does not cover enough tax.

Current status

Current IRS filing guidance — this is not a new law or a newly announced deadline.

Who is affected

Self-employed and 1099 workers, gig workers, and other individuals whose income is not fully covered by withholding. Nonresident aliens use Form 1040-ES (NR).

Effective date

September 15, 2026 is the regular third estimated-tax payment date for calendar-year individuals.

Action to consider

Reconcile income and deductible expenses through August, compare year-to-date payments and withholding with an updated 2026 estimate, and use the correct IRS payment type and tax year if a payment is due.

Limited applicability: Special rules and qualifying disaster relief can change an individual deadline. The IRS resident-taxpayer interview is not designed for nonresident or dual-status taxpayers.