What 4 Year-End Tax Moves Should You Make Right Now Before December 31?
The calendar is your biggest tax lever. These four clean moves can legally cut thousands off your 2025 tax bill — if you act before the ball drops.
Summary of What This Blog Covers
- Prepay expenses under the 12-month rule + de minimis
- Push cash-basis income into January (no constructive receipt)
- Choose Solo 401(k) or SEP-IRA and fund before deadlines
- Reforecast profit and hit safe harbor exactly
Move 1 – Accelerate Deductible Expenses
Cash-basis → pay in December, deduct in 2025.
Safe plays: insurance ≤12 months, SaaS annual plans, rent, repairs, supplies, Section 179/bonus equipment.
Pro tip: adopt a $2,500 de minimis policy → expense everything under it instantly.
Move 2 – Defer Income to January
Invoice December work in January • Ask clients to pay after Jan 1 • Don’t touch checks sitting in the mailbox.
Cash-basis only — no constructive receipt.
Move 3 – Fund Retirement
Solo 401(k): Must exist by Dec 31 for 2025 deferrals (up to $23,500 employee + 25% employer)
SEP-IRA: Can open & fund by filing deadline — perfect for surprise profits
Move 4 – Reforecast & Hit Safe Harbor on Jan 15
Run a quick December projection → pay exactly 90% of 2025 tax or 100%/110% of 2024 tax.
Precision here = no penalty + no overpayment.
Want your personalized year-end checklist before December 31?
Book a Year-End Tax Sprint with Insogna. We’ll run your numbers, build the exact prepay/defer/retirement/safe-harbor plan, and hand you a one-page checklist. Whether you searched “CPA Austin”, “tax preparer near me”, or “year-end tax planning”, we turn December stress into January calm.
Frequently Asked Questions
1) What can I safely prepay in December?
Anything ≤12 months coverage: insurance, SaaS, rent, dues. Plus repairs, supplies, and Section 179 equipment.
2) How do I defer income without constructive receipt?
Don’t invoice or make payment available until January. Contract notes help.
3) Solo 401(k) vs. SEP — which is better right now?
Want max deferral fast → Solo 401(k) by Dec 31. Want flexibility → SEP by filing deadline.
4) Is bonus depreciation still worth it?
Yes at 60% in 2025, especially after maxing Section 179.
5) How do I hit safe harbor without overpaying?
December projection + exact Jan 15 payment. We run it in 20 minutes.