Trigger phrases:

"What taxes are due this month?"
"When is [entity type]'s tax return due?"
"Set up a tax deadline calendar for [client]"
"When do I need to pay estimated taxes?"
"What's the penalty for filing [form] late?"
"Did we miss any tax deadlines?"
"Extension deadline for [form]?"
"Payroll tax deposit schedule for [company]"
"1099 deadline this year?"
"W-2 due date?"

NOT for:

Preparing or filing tax returns — requires licensed CPA / PTIN
Calculating actual tax liability (income, payroll, sales tax owed)
Multi-state nexus analysis or sales tax registration advice
State-specific filing requirements beyond major deadlines (consult state CPA)
International tax deadlines (FBAR, Form 5471, etc.) — specialized skill needed
Prior-year amended return deadlines beyond standard 3-year lookback guidance

Federal Tax Deadline Reference

Business Entity Filing Deadlines

Entity Type	Form	Standard Deadline	Extended Deadline
S-Corporation	1120-S	March 15	September 15
Partnership	1065	March 15	September 15
C-Corporation (Dec. 31 FYE)	1120	April 15	October 15
C-Corporation (other FYE)	1120	15th day of 4th month after FYE	6-month extension
LLC (single-member, disregarded)	Schedule C / 1040	April 15	October 15
LLC (multi-member, partnership)	1065	March 15	September 15
Non-profit	990 / 990-EZ	15th day of 5th month after FYE	6-month extension
Sole Proprietor	Schedule C / 1040	April 15	October 15
Trust / Estate	1041	April 15	September 30

Key rule: S-Corps and Partnerships file March 15 so that K-1s reach shareholders/partners before the individual April 15 deadline. Missing March 15 cascades to missed individual returns.

Individual Filing Deadlines

Form	Standard Deadline	Extended Deadline	Notes
Individual (1040)	April 15	October 15	Extension via Form 4868
FBAR (FinCEN 114)	April 15	October 15	Auto-extended; no separate filing needed
FATCA (Form 8938)	April 15 (with 1040)	October 15 (with extension)
Gift Tax (709)	April 15	October 15 (with 1040 extension)

Estimated Tax Payment Schedule (Federal)

Applies to: individuals with self-employment income, pass-through owners, sole proprietors.

Payment	Tax Year	Due Date
Q1	January 1 – March 31	April 15
Q2	April 1 – May 31	June 15
Q3	June 1 – August 31	September 15
Q4	September 1 – December 31	January 15 (following year)

If April 15 or other dates fall on a weekend or holiday, the deadline shifts to the next business day.

Safe harbor thresholds (avoid underpayment penalty):

Option A: Pay 100% of prior-year tax liability (110% if prior-year AGI > $150,000)
Option B: Pay 90% of current-year actual tax liability
Use whichever results in lower required payment.

Underpayment penalty rate: Federal funds rate + 3% (IRS adjusts quarterly). Currently ~7-8% annualized.

Payroll Tax Deadlines

Federal Payroll Deposits

Deposit schedule depends on lookback period (July 1 – June 30 of prior year):

Lookback Period Tax Liability	Deposit Schedule	Deposit Deadline
≤ $50,000	Monthly depositor	15th of following month
> $50,000	Semi-weekly depositor	Wed–Fri payroll → following Wednesday; Mon–Tue payroll → following Friday
< $2,500/quarter	Quarterly depositor	With Form 941 filing
$100,000+ in single day	Next-day depositor	Next banking day — no exceptions

Key payroll tax forms and deadlines:

Form	What	Deadline
Form 941	Quarterly payroll tax return	Last day of month following quarter end (Apr 30, Jul 31, Oct 31, Jan 31)
Form 940	Annual FUTA return	January 31 (or Feb 10 if all deposits made on time)
Form W-2	Wage statements to employees	January 31
Form W-3	Transmittal to SSA	January 31
Form W-2 corrections (W-2c)	Corrected wages	ASAP; penalties increase with delay

Form 941 Quarterly Calendar (2026)

Quarter	Period	Filing Deadline	Deposit Deadline (monthly)
Q1	Jan–Mar	April 30, 2026	15th of each following month
Q2	Apr–Jun	July 31, 2026	15th of each following month
Q3	Jul–Sep	October 31, 2026	15th of each following month
Q4	Oct–Dec	January 31, 2027	15th of each following month

Information Return Deadlines

1099 Series

Form	Purpose	Recipient Copy	IRS Paper	IRS E-File
1099-NEC	Non-employee compensation ≥ $600	January 31	January 31	January 31
1099-MISC	Rents, royalties, other income ≥ $600	January 31	February 28	March 31
1099-INT	Interest ≥ $10	January 31	February 28	March 31
1099-DIV	Dividends ≥ $10	January 31	February 28	March 31
1099-R	Retirement distributions	January 31	February 28	March 31
1099-K	Payment card transactions ≥ $5,000 (2024 threshold)	January 31	February 28	March 31
1099-B	Brokerage proceeds	February 15	February 28	March 31

E-file mandate: Filers with 10+ information returns (combined all types) MUST e-file starting 2024. The 10-return threshold replaced the prior 250-return threshold.

W-2 Deadlines

January 31: Send to employees AND file Copy A with SSA (paper AND e-file — same deadline)
No extension available for W-2 filing with SSA without Form 8809

Extension Filing Reference

Form	What	How to File	Extends To
Form 4868	Individual 1040 extension	File by April 15	October 15
Form 7004	Business return extension (1120, 1065, 1120-S)	File by original deadline	+6 months
Form 8868	Non-profit 990 extension	File by original deadline	+6 months
Form 8809	Information return extension (W-2, 1099)	File by original deadline	+30 days (hardship only)

Critical: Extensions extend the TIME TO FILE, not the time to pay. Tax owed must still be estimated and paid by the original deadline or interest + penalties accrue.

Penalty Exposure Calculator

Failure to File (FTF)

FTF Penalty = 5% of unpaid tax per month (or fraction of month) late
Maximum: 25% of unpaid tax
Minimum: greater of $450 (2024) or 100% of tax due if >60 days late

formula:
months_late = ceiling((filing_date - original_due_date).days / 30)
ftf_penalty = min(unpaid_tax * 0.05 * months_late, unpaid_tax * 0.25)
if months_late > 2:
    ftf_penalty = max(ftf_penalty, min(450, unpaid_tax))

Failure to Pay (FTP)

FTP Penalty = 0.5% of unpaid tax per month (reduced to 0.25% if on installment agreement)
Maximum: 25% of unpaid tax
Continues to accrue after filing if balance remains unpaid

formula:
months_unpaid = ceiling((payment_date - original_due_date).days / 30)
ftp_penalty = min(unpaid_tax * 0.005 * months_unpaid, unpaid_tax * 0.25)

Combined FTF + FTP (when both apply)

Combined monthly rate: 5% - 0.5% credit for FTP = 4.5% per month on FTF
After 5 months: FTF maxes at 25%, FTP continues at 0.5%/month until 25% max

Total max combined penalty: 47.5% of unpaid tax (25% FTF + 22.5% FTP at max)

Information Return Penalties (1099/W-2)

Tier 1: Filed within 30 days of deadline → $60/return (max $220,000/year; $75K for small biz)
Tier 2: Filed by August 1 → $120/return (max $660,000/year; $200K for small biz)
Tier 3: Filed after August 1 or not filed → $310/return (max $3.78M/year; $588K for small biz)
Intentional disregard: $630/return with no cap

Small business definition: Average annual gross receipts ≤ $5M for 3 prior tax years.

Payroll Tax Failure to Deposit (FTD)

1-5 days late:   2% of undeposited tax
6-15 days late:  5% of undeposited tax
16+ days late:  10% of undeposited tax
Demand from IRS: 15% of undeposited tax

2026 Key Dates Calendar

JANUARY 2026
  Jan 15  — Q4 2025 estimated tax payment (individuals)
  Jan 31  — W-2s to employees
  Jan 31  — 1099-NEC to recipients AND to IRS
  Jan 31  — Form 940 (FUTA annual return)
  Jan 31  — Form 941 Q4 2025

FEBRUARY 2026
  Feb 15  — 1099-B to recipients (brokerage)
  Feb 28  — 1099-MISC / 1099-INT / 1099-DIV to IRS (paper filers)

MARCH 2026
  Mar 15  — S-Corp (1120-S) and Partnership (1065) returns DUE
  Mar 15  — S-Corp / Partnership extension deadline (Form 7004)
  Mar 31  — 1099-MISC / 1099-INT / 1099-DIV to IRS (e-filers)

APRIL 2026
  Apr 15  — Individual (1040) return DUE
  Apr 15  — C-Corp (1120, Dec 31 FYE) return DUE
  Apr 15  — Individual extension deadline (Form 4868)
  Apr 15  — Q1 2026 estimated tax payment
  Apr 30  — Form 941 Q1 2026

JUNE 2026
  Jun 15  — Q2 2026 estimated tax payment

JULY 2026
  Jul 31  — Form 941 Q2 2026

SEPTEMBER 2026
  Sep 15  — S-Corp / Partnership extended returns DUE (if extended)
  Sep 15  — Q3 2026 estimated tax payment
  Sep 30  — Trust/Estate (1041) extended return DUE

OCTOBER 2026
  Oct 15  — Individual (1040) extended return DUE
  Oct 15  — C-Corp (1120) extended return DUE
  Oct 31  — Form 941 Q3 2026

JANUARY 2027
  Jan 15  — Q4 2026 estimated tax payment
  Jan 31  — Form 941 Q4 2026 / W-2s / 1099-NECs

Compliance Checklist Generator

When a user asks for a client compliance calendar, generate a checklist:

Inputs required:

□ Entity type (S-Corp, C-Corp, Partnership, LLC, Individual, Non-profit)
□ Tax year end (calendar year = Dec 31, or fiscal year end date)
□ Number of employees (for payroll obligations)
□ Number of 1099 vendors (for information return obligations)
□ State(s) of operation
□ Whether entity makes estimated tax payments

Output: Client Compliance Checklist

CLIENT: [Name] | ENTITY: [Type] | TAX YEAR: 2025

INFORMATION RETURNS (January–March):
  [ ] Jan 31: Send W-2s to [X] employees
  [ ] Jan 31: Send 1099-NECs to [X] contractors
  [ ] Jan 31: File W-3 + W-2 copies with SSA
  [ ] Jan 31: File 1099-NECs with IRS
  [ ] Mar 31: File remaining 1099s with IRS (if e-filing)

ENTITY RETURN:
  [ ] [March 15 / April 15]: File [1120-S / 1065 / 1040 / 1120]
  [ ] [Same date]: Pay any balance due (extension ≠ extension to pay)
  [ ] If extending: File Form [4868 / 7004] by original deadline

ESTIMATED TAXES (if applicable):
  [ ] Apr 15, Jun 15, Sep 15, Jan 15 — $[amount] each installment

PAYROLL TAXES (if employees):
  [ ] Monthly/semi-weekly deposits per schedule
  [ ] Apr 30 / Jul 31 / Oct 31 / Jan 31: Quarterly Form 941
  [ ] Jan 31: Annual Form 940 (FUTA)

NOTES:
  - State return deadlines: [list state-specific deadlines here]
  - Any pending elections or forms: [e.g., S-election, 1045, etc.]

State Tax Deadline Overview

Most states conform to federal deadlines, but key exceptions:

State	Notable Difference
California	FTB: C-Corp April 15; S-Corp March 15; Individual April 15 (or next business day)
New York	Conforms to federal dates; NYC adds separate NYC-4S/NYC-4 for C-Corps
Texas	No state income tax; franchise tax (TX No Tax Due/05-163) due May 15
Florida	C-Corp F-1120 due: April 1 (or 4.5 months after FYE)
Illinois	Conforms to federal with IL-specific extensions
Pennsylvania	Conforms to federal for individuals; RCT-101 for C-Corps April 15

Always verify: State deadlines change. Use this as a starting framework, not the definitive source. Confirm with state revenue department or state-licensed CPA.

Reminder Setup (OpenClaw Cron)

To set up automated deadline reminders via cron:

Recommended lead times:
  - 30 days before: "Coming up" awareness notice
  - 14 days before: Action required — gather documents
  - 7 days before:  Final prep — return should be in progress
  - 1 day before:   Due tomorrow — confirm filed/extension submitted

Sample cron payload (S-Corp March 15 deadline):

{
  "schedule": { "kind": "at", "at": "2026-03-01T09:00:00-06:00" },
  "payload": {
    "kind": "systemEvent",
    "text": "TAX REMINDER: S-Corp/Partnership returns (Form 1120-S / 1065) due March 15 — 14 days away. Confirm K-1s being prepared, extension decisions made, and balance due estimated."
  }
}

Penalty Abatement Notes

First-time penalty abatement (FTA):

Available for FTF, FTP, and FTD penalties
Requires: clean compliance history (no penalties in prior 3 years) + all returns filed
Request via Form 843 or by calling the IRS
IRS grants FTA liberally — always ask before paying FTF/FTP penalties

Reasonable cause abatement:

Available when failure was due to circumstances beyond taxpayer's control
Document: what happened, why it prevented compliance, steps taken to comply ASAP
Examples: natural disaster, serious illness, reliance on erroneous IRS advice

Integration Points

qbo-automation — Pull payroll and vendor payment data to identify 1099 filing obligations
crypto-tax-agent — Crypto tax events feed into individual 1040 and Schedule D deadlines
kpi-alert-system — Trigger compliance calendar reminders via cron/alert system
compliance-monitor — Broader compliance tracking beyond tax deadlines
startup-financial-model — Estimated tax payments flow from projected taxable income model

Quick Reference: Most Common Deadline Misses

1099-NEC January 31 — Most commonly missed information return (same day recipient AND IRS)
S-Corp March 15 — Founders forget pass-through entities file earlier than individuals
Estimated Q1 taxes April 15 — Individual owners skip this and face underpayment penalty
Form 940 January 31 — FUTA often forgotten since it's only annual
Extension ≠ payment extension — Filing an extension without paying causes FTP penalties to accrue

tax-deadline-calendar

Tax Deadline Calendar Skill

When to Use This Skill