One Hour in December: The Year-End Tax Moves That Put Real Money Back in Your Pocket

Here's an uncomfortable truth about taxes: by the time you're sitting down with a CPA in March, most of your opportunities are gone. The tax year is closed. The moves that actually matter happen in December, while there's still time to act.

The good news? For most freelancers and side hustlers, this is about one focused hour with a cup of coffee and a laptop. Here's the checklist, in plain English, no accounting degree required.

1. Hunt Down the Deductions You Forgot You Qualified For

Most side hustlers know the classics — supplies, software, the home office deduction. But a few commonly missed ones are worth real money:

• Mileage. The IRS rate (over 60 cents per mile for 2024, and check the current-year rate) adds up fast. Drove to pick up supplies? Meet a client? Grab a coffee with a collaborator to talk shop? Log it now, while you still remember.
• A portion of your phone and internet bill, if you use them for the business.
• Self-employed health insurance premiums, which can be deducted against your business income.
• Bank fees, payment processing fees, and that monthly website hosting charge you've been autopaying all year and forgot about.
• Professional development — courses, books, even a conference ticket, if it relates to your business.

The rule of thumb: ordinary and necessary for your business. When in doubt, log it and ask a pro.

2. Spend Down Your HSA and FSA (and Buy What You Already Needed)

If you have a Health Savings Account, contributions for the year can generally be made up until the tax filing deadline — but if you have a Flexible Spending Account, those dollars often expire or shrink at year-end. December is when you check your FSA balance and use it: glasses, prescription sunglasses, eligible pharmacy items.

If you're self-employed with an HSA, a contribution before the deadline is an above-the-line deduction — one of the few you can make even after December 31 in some cases. Either way, this is five minutes of checking that can be worth hundreds.

3. Time Your Income and Expenses Like a Chess Player

This is the move that surprises people. Because most side hustlers are on cash-basis accounting, you control — within reason — which year income and expenses land in.

Expecting a big invoice to be paid in early January? If you can legitimately invoice it in late December, it counts this year. Expecting a lower-income year next year? Delay it and let it land where your tax bracket is friendlier.

On the flip side: need new equipment, software, or stock for next year anyway? Buy it in December. Business expenses you were going to spend in January can reduce this year's taxable income instead. It's not aggressive tax planning — it's just timing, and it's completely legal.

4. Make a Retirement Contribution (Yes, Even Solo)

You don't need an employer to shelter income. A Traditional IRA or a SEP-IRA works for side income, and a SEP-IRA lets you contribute up to roughly 20–25% of net self-employment earnings — often much more than an IRA limit.

A SEP-IRA can generally be opened and funded up until your filing deadline, but opening it now while you're thinking about it means the option is on the table. Every dollar contributed is a dollar that isn't taxed this year. If you made $10,000 from your hustle and put $2,000 into a SEP, you've just cut your taxable side income by a fifth.

5. Get Your Business Structure Sorted Before January 1

This is the deadline people miss. If your side hustle has grown past hobby territory — real revenue, real liability risk — forming an LLC (and, depending on your situation, electing S-corp treatment for the following year) is a move to make in December, not spring.

An LLC separates your personal assets from your business liabilities. An S-corp election, once your profits clear roughly $40–50K, can potentially save thousands in self-employment tax — though it adds payroll requirements, so talk to a pro before jumping.

The key point: entities and elections generally need to be in place by January 1 to count for the new tax year. December is your window.

The One-Hour Game Plan

Here's your actual to-do list, in order:

1. Pull your bank and card statements and log every business expense (20 minutes).
2. Total your mileage and photograph your odometer (5 minutes).
3. Check your FSA balance and spend it down (5 minutes).
4. Decide on income/expense timing with your calendar in front of you (10 minutes).
5. Call a CPA or book a consult about entity structure and retirement contributions (20 minutes).

One hour. That's the whole ask. And unlike most hours you'll spend on your business this month, this one has a known, quantifiable return.

April-you will be very grateful.