tax-deadline-calendar（纳税期限日历）

Tax Deadline Calendar Skill

Track federal and state tax filing deadlines, estimated tax payment windows, payroll deposit schedules, and information return due dates. This skill helps Sam Ledger proactively manage compliance calendars, generate reminders, and calculate penalty exposure for late filings.

When to Use This Skill

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

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

Estimated Tax Payment Schedule (Federal)

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

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):

Key payroll tax forms and deadlines:

Form 941 Quarterly Calendar (2026)

Information Return Deadlines

1099 Series

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

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:

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

1. 1099-NEC January 31 — Most commonly missed information return (same day recipient AND IRS)
2. S-Corp March 15 — Founders forget pass-through entities file earlier than individuals
3. Estimated Q1 taxes April 15 — Individual owners skip this and face underpayment penalty
4. Form 940 January 31 — FUTA often forgotten since it's only annual
5. Extension ≠ payment extension — Filing an extension without paying causes FTP penalties to accrue