Filing your taxes in April is reporting. The decisions that actually change the number all happen before December 31. Here’s the checklist.
By Gabe Nelson, CFP® · Gabe Nelson Financial, Inc. · ~6 min read
There’s a quiet myth that costs high-earning solopreneurs tens of thousands of dollars a year: the idea that “tax season” is April. It isn’t. By the time you’re sitting across from your CPA in the spring, every number on your return is already locked. Filing is just reporting what already happened. The season that actually decides your tax bill — the one where you can still change the outcome — is happening right now, in the fourth quarter.
I’m Gabe Nelson, a CFP® who works with high-earning solopreneurs nationwide. My job is to help you stop overpaying in taxes, build wealth that compounds automatically, and create the option to make work voluntary on your timeline. And nowhere is the gap between planning and reporting more expensive than in the last three months of the year.
Here’s why: nearly every meaningful tax move has a hard December 31 wall in front of it. Miss the date and the door closes until next year. So instead of another abstract lecture, here’s the actual checklist — the six moves that require Q4 action.
One note before the list. This gets more expensive the more you earn, not less. At $500,000, $700,000, or a million dollars of income, the gap between planning these moves in the fourth quarter and reacting to them in April can be tens of thousands of dollars — every single year, compounding over a career. The people with the most to gain from year-end planning are almost always the ones too busy running a great business to stop and do it.
- Fund your retirement plans
Your Solo 401(k) and, if you have one, a Cash Balance Plan are the biggest levers most high earners have — and they carry the earliest deadlines. Solo 401(k) employee contributions generally have to be elected and largely handled by year-end, and a Cash Balance Plan usually has to be established by December 31 to count for the current year. These plans can shelter far more than most solopreneurs realize — often multiples of what a Solo 401(k) allows on its own — but only if the paperwork and funding happen on time. Wait until April and this year’s opportunity is simply gone.
- Run your Roth conversion analysis
A Roth conversion moves money from a tax-deferred account into a Roth, where it grows and eventually comes out tax-free. You pay tax on the converted amount now, at today’s rate — which is exactly why timing is everything. If this is a low-income year for you, converting while your bracket is temporarily low can be one of the best deals in the tax code. But a conversion has to be completed by December 31 to land in this tax year. There’s no “do it in April for last year.”
- Decide whether to push or book income
As a solopreneur, you often control when your income lands — and that timing helps decide your bracket. In a high year, you might “push” a December invoice into January so the income, and its tax, falls into a lower-bracket year. In an unusually low year, you might “book” income now to fill the cheap brackets on purpose. A W-2 employee can’t move a paycheck; you can move an invoice. But the decision has to be made before the year ends.
- Accelerate your deductions
A deduction is worth your marginal tax rate, so the same expense is worth more in a high-income year than a low one. Prepaying legitimate business expenses — next year’s software subscriptions, insurance premiums, certain supplies — before December 31 pulls those deductions into this year. The expense has to be real and actually incurred, not just money parked with a vendor, and cash-basis rules decide what counts. This is a coordinate-with-your-CPA move, not one to freelance in late December.
- Harvest your investment losses
In your taxable brokerage account, selling positions that are down locks in losses that offset your capital gains — plus a few thousand dollars of ordinary income beyond that. If you took a big gain this year, harvesting losses against it before year-end can erase a chunk of the bill. Watch the wash-sale rule — you can’t buy the same position back within 30 days — but you can stay invested in something similar to keep your exposure. Like everything else here, the loss only counts if you realize it before the calendar flips.
- Bundle your charitable giving
If you give to charity, “bundling” several years of planned giving into one high-income year — often through a donor-advised fund — captures the deduction when it’s worth the most. You take the tax benefit in the year you fund the account, then grant the money out to charities over time. The contribution has to be in by December 31.
Six moves. Every one has a December 31 wall. And every one is invisible in April — because by then, the window has already closed.
What this looks like in real life
Consider two solopreneurs — call them David and John. Both earn around $900,000. Both are diligent savers. Both have a capable CPA. The only difference: John started his tax planning in October, and David called his accountant in April.
In the fourth quarter, John funded a Cash Balance Plan, harvested some losses against a gain he’d realized earlier in the year, and prepaid a portion of next year’s software and insurance. His CPA ran the numbers while there was still time to act on them. Same income, same tax code — John’s Q4 moves saved him roughly $40,000 over what David paid.
David’s CPA didn’t fail him. By April, there was genuinely nothing left to do but add up a year that was already over. And that’s the point worth sitting with: the issue is almost never your CPA’s capability. Filing is an annual, reactive job. Proactive, multi-year planning is a separate conversation — one that has to happen in Q4, and one that too often nobody schedules. Coordinating that planning, sitting between you and your CPA, is exactly the work I do.
Your move
Ask yourself three questions. When do I actually think about my taxes — in Q4, when I can change them, or in April, when I can only report them? Of these six moves, how many have I ever had a real conversation about? And is anyone running my numbers before December 31, while there’s still time?
If your entire tax life happens in April, you don’t have a tax strategy. You have a tax report. There’s a world of difference between the two — and only a few weeks left this year to close it.
You don’t have to run all six moves. Most solopreneurs only need two or three of them in any given year — the trick is knowing which ones fit your situation, and getting to them before the deadline forces the decision for you. That’s the difference between a checklist you glance at and one you actually execute: someone sitting down with your numbers, in the fourth quarter, deciding what applies while there’s still time to act on it. Treat this list as the agenda for that conversation, not a substitute for it.
Running these six moves before year-end, in coordination with your CPA, is exactly what a Year-End Tax Strategy Session is for. Book one at StartWithGabe.com, or download the free Scaling Wealth Blueprint to see the system I use with solopreneurs.
The best time to start was years ago. The second best time is right now.
Educational only — not personalized tax, legal, or investment advice. Client details are anonymized composites and figures are illustrative; tax deadlines, brackets, and limits change from year to year. Coordinate with your CPA and confirm current rules before acting. Gabe Nelson is an Investment Adviser Representative; advisory services are offered through Gabe Nelson Financial, Inc.