⚠️ Important Note: This calendar outlines ALL submission deadlines and requirements for S-Corporation owners. Items marked with specific months require action by you (the business owner) to submit documents to your CPA or complete required filings. Review this calendar at the beginning of each month to stay compliant.
MONTHLY TASKSEvery Month
Monthly Bookkeeping Submission
Submit bank statements, credit card statements, and receipts to your bookkeeper or CPA by the 5th of each month. Include documentation of business purpose for all expenses. Respond promptly to any questions about uncategorized transactions—delays in clarifying these items can hold up your monthly close and quarterly review.
📅Deadline: 5th of each month
📦Submit to: Bookkeeper/CPA
📋Required: Bank/CC statements, receipts
⚡Action: Answer uncategorized transaction questions within 48 hours
Payroll Processing & Reporting
Process payroll for yourself and any employees. Ensure payroll taxes are deposited timely (typically next business day or within 3 days depending on deposit schedule).
📅Frequency: As scheduled (weekly, bi-weekly, etc.)
🏢Handled by: Payroll service
⚠️Critical: Tax deposits must be on time
Expense Reimbursement Submission
Submit Accountable Plan expense reimbursement form with supporting documentation. Include mileage, home office, business expenses, and any other reimbursable items.
📅Deadline: 10th of each month (for prior month)
📋Required: Expense form, receipts, mileage log
⚠️Critical: Must be contemporaneous documentation
Mileage Tracking
Track all business mileage with date, starting location, destination, business purpose, and miles driven. Use MileIQ, Everlance, or manual mileage log.
📱Tools: MileIQ, Everlance, TripLog
📋Required: Date, locations, purpose, miles
💰2025 Rate: $0.70/mile
Child/Family Time Sheet (if applicable)
Submit time sheets for any employed children or family members. Include specific tasks performed, hours worked, and dates.
📅Deadline: 10th of each month
📋Required: Tasks, hours, dates, signature
⚠️Critical: Reasonable wages for actual work
QUARTERLY TASKSEvery Quarter
Estimated Tax Payments (Federal & State)
Pay quarterly estimated taxes for personal income tax liability not covered by withholding. Due dates: April 15, June 15, September 15, January 15.
📅Due: 4/15, 6/15, 9/15, 1/15
📋Forms: 1040-ES (Federal), State voucher
⚠️Penalty for underpayment
Quarterly Strategic Planning Meeting
60–90 minute session with your advisor to review YTD performance, update tax projections, and plan next quarter strategies. Schedule in advance.
📅Timing: End of each quarter
📋Prepare: YTD P&L, questions, major decisions
Board/Advisory Meeting & Minutes
Conduct quarterly board or advisory meeting. Document attendance, topics discussed, decisions made, and any resolutions passed.
📅Timing: Quarterly (min. annual)
📋Forms: Meeting minutes template
⚠️Required for corporate compliance
Quarterly 941 Filing (Payroll)
File Form 941 for quarterly payroll tax reporting. Usually handled by payroll provider but verify completion.
📅Due: Last day of month following quarter
🏢Handled by: Payroll service
📋Form: 941
ANNUAL TASKSYearly
W-2s and 1099s
Issue W-2s to all employees and 1099s to independent contractors paid $600+ during the year.
📅Due: January 31
📋Forms: W-2, 1099-NEC
⚠️Penalty for late/incorrect filing
S-Corp Tax Return (Form 1120S)
File S-Corporation tax return with IRS and state. Generates K-1 for shareholders.
📅Due: March 15 (or extension Sept 15)
📋Form: 1120S + State return
🏢Prepared by: CPA
Personal Tax Return (Form 1040)
File personal income tax return including K-1 from S-Corporation.
📅Due: April 15 (or extension Oct 15)
📋Form: 1040 + State return
🏢Prepared by: CPA
Year-End Tax Planning Meeting
Comprehensive year-end planning session to maximize deductions, plan equipment purchases, and implement final strategies before December 31.
📅Timing: November (before year-end)
📋Prepare: YTD financials, planned purchases
Reasonable Compensation Review
Annual review of shareholder W-2 salary to ensure it remains reasonable based on current industry data and business performance.
📅Timing: Q4 annually
📋Document: Updated compensation memo
Annual Mileage Summary
Compile annual mileage summary including odometer readings at start and end of year, total business miles, and business use percentage.
📅Due: December 31 (odometer reading)
📋Required: Start/end odometer, total business miles
Form 940 (FUTA) Filing
File annual Federal Unemployment Tax Act return. Required for all employers who paid wages of $1,500+ in any quarter or had employees for 20+ weeks.
📅Due: January 31
📋Form: 940
🏢Handled by: Payroll service or CPA
⚠️Penalty for late filing
PTET Election (State-Specific)
File Pass-Through Entity Tax election if applicable. Deadlines vary by state—IL: due with return; CA: due by original return deadline; NY: March 15. Check your state's specific requirements.
Solo 401(k) must be adopted by December 31 for current year contributions. SEP-IRA can be established until tax filing deadline. Contributions due by filing deadline (including extensions).
📅Solo 401(k) Adoption: December 31
📅Contributions: Tax filing deadline + extensions
📋Strategies #18-19
HSA Contribution Deadline
Contributions for prior year can be made until April 15 tax filing deadline. 2025 limits: $4,300 (self-only) / $8,550 (family) + $1,000 catch-up if 55+.
📅Due: April 15 (for prior year)
📋Strategy #22 — Triple tax advantage
⚠️Must have HDHP coverage
State Annual Report / Franchise Tax
File state annual report and pay any franchise taxes. IL Annual Report due by anniversary; CA $800 minimum franchise tax; other states vary. Check your state's requirements.
📅Due: Varies by state
📋Forms: State-specific annual report
⚠️Failure to file can result in administrative dissolution
S-Corp Health Insurance W-2 Reconciliation
Reconcile health insurance premiums paid for >2% shareholders. Ensure premiums are included in W-2 Box 1 (but not Box 3 or 5) before year-end payroll.
📅Timing: Before final payroll of year
📋Strategy #2 — §162(l)
⚠️Must be on W-2 to claim 1040 deduction
Augusta Rule Documentation
Compile 14-day rental documentation including rental agreement, meeting agendas/minutes, FMV comparable rate support, and payment records.
📅Timing: Year-end (compile all meetings)
📋Strategy #4 — §280A(g)
📋Required: Agreement, minutes, FMV support
AS-NEEDED TASKSEvent-Triggered
1031 Exchange Deadlines
Critical deadlines for like-kind exchanges: 45 days to identify replacement property, 180 days to close. No extensions available. Use qualified intermediary.
📅45-Day ID: Strict deadline from sale
📅180-Day Close: Strict deadline from sale
📋Strategy #40 — §1031
⚠️NO EXTENSIONS — Miss deadline = taxable event
Section 83(b) Election
Election to recognize income on restricted stock at grant date (low value) rather than vesting date (potentially high value). Must be filed within 30 days of grant—no exceptions.
📅Due: 30 days from grant date
📋Strategy #51a — §83(b)
⚠️NO EXTENSIONS — Missed = Cannot file late
Annual Calendar Overview
Quarterly deadline months highlighted. Review at the start of each month.
JANUARY
✓ Q4 Estimated Tax (15th)
✓ W-2s & 1099s (31st)
✓ Form 940 FUTA (31st)
✓ Monthly tasks
FEBRUARY
✓ Business docs to CPA (28th)
✓ Monthly tasks
MARCH
✓ 1120S Due (15th)
✓ PTET Election (state-specific)
✓ Personal docs to CPA (31st)
✓ Monthly tasks
APRIL
✓ 1040 Due (15th)
✓ Q1 Estimated Tax (15th)
✓ HSA Prior Year (15th)
✓ Quarterly meeting
✓ Monthly tasks
MAY
✓ Monthly tasks
✓ Mid-year planning
JUNE
✓ Q2 Estimated Tax (15th)
✓ Quarterly meeting
✓ Monthly tasks
JULY
✓ Monthly tasks
✓ Mid-year review
AUGUST
✓ Monthly tasks
✓ Q3 planning
SEPTEMBER
✓ Q3 Estimated Tax (15th)
✓ Extended 1120S (15th)
✓ Quarterly meeting
✓ Monthly tasks
OCTOBER
✓ Extended 1040 (15th)
✓ Year-end planning begins
✓ Monthly tasks
NOVEMBER
✓ Year-end tax meeting
✓ Strategy implementation
✓ Monthly tasks
DECEMBER
✓ Solo 401(k) adoption (31st)
✓ Health ins W-2 reconciliation
✓ Augusta Rule docs compiled
✓ Final year-end actions
✓ Equipment purchases
✓ Annual mileage summary (31st)
✓ Monthly tasks
💡 Pro Tips for Staying Compliant
Set calendar reminders for all monthly and quarterly deadlines
Use automated tracking tools (MileIQ for mileage, Expensify for expenses)
Document in real-time – don't wait until month-end to record business purposes
Keep digital and physical copies of all compliance documents for 7 years
Submit early – don't wait until the deadline to avoid processing delays
Ask questions – reach out to your advisor immediately if uncertain about any requirement