2026 tax deadlines for Boise businesses and families
The dates that matter this year, in one place. Bookmark this page so a filing deadline never sneaks up on you again.
Last reviewed July 7, 2026. These are the federal deadlines for the 2026 filing season; Idaho state returns follow the same April date. Weekends and holidays are already accounted for below.
- Everyone
Q4 2025 estimated tax payment due
Final quarterly estimated payment for the 2025 tax year for self-employed individuals, business owners, and anyone with income not subject to withholding.
- Businesses
W-2s and 1099-NEC forms due
Employers must furnish W-2s to employees, and businesses must send 1099-NEC forms to contractors and file them with the IRS. (January 31 falls on a Saturday in 2026, so the deadline moves to the next business day.)
- Businesses
S-corporation and partnership returns due
Calendar-year S-corporations (Form 1120-S) and partnerships (Form 1065) must file their returns or request a six-month extension. (March 15 falls on a Sunday in 2026.)
- Everyone
Tax Day: individual and C-corp returns due
The big one. Individual returns (Form 1040), Idaho state returns (Form 40), and C-corporation returns (Form 1120) are due. Also the deadline for the Q1 2026 estimated payment and for 2025 IRA and HSA contributions. Any tax owed is still due today, even if you file an extension.
- Everyone
Q2 2026 estimated tax payment due
Second quarterly estimated payment for the 2026 tax year.
- Everyone
Q3 estimated payment + extended business returns due
Third quarterly estimated payment for 2026, and the final deadline for S-corporations and partnerships that filed an extension in March.
- Everyone
Extended individual and C-corp returns due
Final deadline for individual and C-corporation returns that were put on extension back in April. After this, late-filing penalties begin.
- Everyone
Q4 2026 estimated tax payment due
Final quarterly estimated payment for the 2026 tax year, closing out the year.
Dates can shift for disaster relief or special IRS announcements. If your situation involves fiscal-year filing, multiple states, or an extension, Laura can map your exact deadlines. When in doubt, call (208) 321-2575.
Want these deadlines handled for you?
Laura keeps her clients ahead of every filing date, so you're never scrambling in April. Schedule a complimentary consultation and put a CPA on your calendar.