Year-End Tax Planning Playbook

Why Year-End Matters

Most tax strategies have a deadline: December 31st.

After that, the year is closed. The decisions are made. You're locked in.

This playbook walks you through October, November, and December — the critical window when proactive planning turns into real savings.

October: Assess and Plan

Goal: Know your numbers. Create a written plan.

Week 1–2: Get Current

Ensure books are up to date through September
Pull year-to-date P&L
Estimate October–December income and expenses
Calculate projected full-year profit

Your projected profit:

Week 3–4: Identify Opportunities

Review each category and note action items:

Entity & Salary (S-Corps)

Is salary reasonable? Adjust if needed before final payroll
Are distributions appropriate?

Retirement Contributions

What's my current contribution?
What's my maximum contribution?
Gap to fund before year-end:

Equipment Purchases

Any equipment I've been considering?
Would Section 179 deduction be valuable this year?
List items:

Income Timing

Can any collections be deferred to January?
Any large payments expected that could be delayed?

Expense Timing

Any expenses I can prepay before December 31st?
Supplies to order? Insurance to prepay?

End of October Deliverable: Written plan with specific actions, amounts, and deadlines.

November: Prepare and Begin Executing

Goal: Get everything lined up. Start executing.

Week 1–2: Confirm and Prepare

Review plan with accountant (if applicable)
Confirm retirement plan contribution amounts
Get quotes for equipment purchases
Verify cash flow can support planned actions

Week 3–4: Begin Execution

Retirement

Initiate retirement contributions (Solo 401(k) employee contributions due by Dec 31)
If setting up a new Solo 401(k), establish plan by December 31st

Equipment

Place orders for equipment purchases
Ensure delivery/payment before December 31st

Salary Adjustments (S-Corps)

If adjusting salary, coordinate with payroll
Plan final payroll timing

Documentation

Update mileage log through current date
Gather home office expense documentation
Organize any missing receipts

End of November Deliverable: All major actions initiated. Final December tasks identified.

December: Execute and Close

Goal: Complete all year-end actions. Close the year clean.

Week 1–2: Final Execution

Complete any remaining equipment purchases
Make final retirement contributions (or schedule them)
Process final payroll with correct salary (S-corps)
Pay any bills you want as current-year deductions

Week 3: Last-Minute Items

By December 20th:

Final retirement contributions made or scheduled
All equipment received and paid for
Final payroll processed

Timing reminder: Many financial institutions slow down around the holidays. Don't wait until December 30th.

Week 4: Documentation and Close

Finalize mileage log for the year
Save all receipts and documentation
Note any items to address in January
Schedule Q1 planning conversation

December 31st Deadlines

Item	Deadline
Solo 401(k) employee contributions	Dec 31
Establishing new Solo 401(k)	Dec 31
Equipment purchases (Section 179)	Dec 31
Cash-basis expense deductions	Dec 31
Income deferral (cash-basis)	Dec 31

Note: Some contributions (SEP, employer portion of Solo 401(k)) can be made until tax filing deadline, but the plan must exist by Dec 31.

Quick Reference: Common Year-End Actions

Strategy	Potential Impact	Complexity
Max out retirement contributions	High ($10,000–$50,000+ in tax savings)	Low–Medium
Section 179 equipment purchase	Medium ($5,000–$20,000+)	Low
Prepay expenses	Low–Medium ($1,000–$5,000)	Low
Adjust S-corp salary	Medium (varies)	Medium
Defer income to next year	Medium (timing-dependent)	Low
Establish Cash Balance Plan	Very High ($50,000–$100,000+)	High

Year-End Planning Meeting Agenda

If you're meeting with your accountant, here's what to cover:

Current position: Year-to-date profit, projected full-year
Tax projection: What am I looking at in taxes?
Opportunities: What strategies should we consider?
Action items: What specifically should I do, by when?
Next year: Any structural changes to consider for January?

After Year-End: January Checklist

Final books closed for prior year
All documents gathered for tax prep
W-2s issued (S-corps) by January 31
1099s issued to contractors by January 31
Q4 estimated tax paid by January 15
Consider S-corp election for new year (Form 2553 due March 15)

Your Year-End Commitment

The difference between a reactive tax bill and a proactive tax strategy often comes down to these three months.

Commit to this:

One planning session in October
Execution in November
Completion in December

That's it. Three months of attention for a year of better outcomes.