Tools
Tax deadlines
Federal, FBAR and California dates for the next fifteen months, already moved for weekends and holidays.
Last reviewed Oct 2026
The main dates for Kit's clients, not every deadline there is.
An IRS or FTB disaster postponement overrides these dates. Check the current list before relying on one.
Each date carries a reminder a week before (Apple Calendar keeps it; Google Calendar uses your own default).
November 2026
2025 extended California C corporation return (100) due
Source:FTB: business due dates
January 2027
2026 estimated tax, payment 4 of 4
California: 30% of the year's estimate.
February 2027
2026 W-2 and 1099-NEC due to workers and to the SSA / IRS
Source:IRS: Form W-2 and W-3 instructionsIRS: Form 1099-MISC and NEC instructions
March 2027
2026 returns: suggested date to bring your documents to Kit
Kit's suggestion, not a legal deadline
Earlier if you have a foreign trust, company or fund (Forms 3520-A, 5471, 8865, 8621).
Source: Kit's intake worksheet
2026 partnership and S corporation returns due (1065, 1120-S, California 100S, 565 and 568)
Form 7004 extends the federal returns six months. A single-member LLC owned by an individual files California 568 by April 15.
Source:IRS: Form 1065 instructionsIRS: Form 1120-S instructionsFTB: business due dates
2026 Form 3520-A due for a foreign trust with a U.S. owner
Form 7004 extends it six months. Extending your own return does not extend Form 3520-A.
Source:IRS: Form 3520-A instructionsIRS: Form 7004 instructions
April 2027
2026 Form 1040 and California 540 due, and any tax owed
Federal: extend with Form 4868; California: automatic, no form. Either way, until October 15 to file, not to pay.
2026 FBAR (FinCEN 114) and Form 3520 due
The FBAR extends automatically to October 15. Form 3520 extends with your return.
2027 estimated tax, payment 1 of 4
California: 30% of the year's estimate.
2026 C corporation returns due (1120, California 100)
Federal extension to October 15; California to November 15.
2027 California LLC $800 annual tax due (Form 3522)
Source:FTB: LLC filing
June 2027
2026 returns and Form 3520 due if you live and work outside the U.S.
An automatic two months, for Form 1040 and California 540 alike; California also covers anyone traveling abroad on April 15. Interest on unpaid tax still runs from April 15.
Source:IRS: 2-month extension abroadFTB: personal due datesIRS: Form 3520 instructions
2026 Form 1040-NR due if you had no U.S. wages with withholding and no U.S. office
With U.S. wages subject to withholding, or an office or place of business in the U.S., Form 1040-NR is due April 15.
2027 estimated tax, payment 2 of 4
California: 40% of the year's estimate.
2027 California LLC fee estimate due (Form 3536)
Only for an LLC whose California income is $250,000 or more.
Source:FTB: LLC filing
September 2027
2027 estimated tax, payment 3 of 4
California: no payment due for this installment.
2026 extended 1065, 1120-S and California 100S due
2026 extended Form 3520-A due
Source:IRS: Form 3520-A instructionsIRS: Form 7004 instructions
October 2027
2026 extended Form 1040 and California 540 due
2026 FBAR (automatic extension) and extended Form 3520 due
2026 extended C corporation return (1120) due
Source:IRS: Form 1120 instructions
2026 extended California 565 and 568 due (partnerships and LLCs)
California's extension is automatic and needs no form, but it does not extend the $800 annual tax or the LLC fee.
November 2027
2026 extended California C corporation return (100) due
Source:FTB: business due dates
January 2028
2027 estimated tax, payment 4 of 4
California: 30% of the year's estimate.
2027 W-2 and 1099-NEC due to workers and to the SSA / IRS
Source:IRS: Form W-2 and W-3 instructionsIRS: Form 1099-MISC and NEC instructions