Year-End Tax Checklist for Freelancers (2026): Moves Before Dec 31

Why December Is the Real Tax Deadline

The April filing deadline is when your tax becomes official, but almost every decision that changes it happens in December. For a US freelancer, December 31 is the line between what belongs in tax year 2026 and what lands in 2027—income, expenses, retirement elections and equipment purchases all snap to that date. Acting in the last quarter of the year is the difference between optimizing your 2026 tax and merely reporting it.

1. Elect Your Solo 401(k) Deferrals by December 31

If you have a Solo 401(k), your 2026 employee salary deferral must be elected by December 31, 2026—the deadline follows the plan year, not your tax return. In 2026 you can defer up to $24,500, plus an $8,000 catch-up if you are 50 or older ($11,250 if you are 60–63). Miss the election and that opportunity is gone for the year, even though employer profit-sharing can still be funded later.

If you do not have a plan yet, a SEP IRA is the easier year-end answer: it can be established and funded as late as your 2026 filing deadline, including extensions (April 15 or October 15, 2027), with contributions up to 20% of net earnings capped at $72,000.

2. Time Equipment and Big Deductible Purchases

Under Section 179, most small businesses can deduct the full cost of qualifying equipment in the year it is placed in service. A laptop, camera, tools or furniture bought and put into use by December 31, 2026 can reduce your 2026 taxable income in full. Wait until January and the deduction belongs to 2027—so if you were planning the purchase anyway and your 2026 profit justifies it, year-end is the moment to pull the trigger.

The same logic applies to subscriptions, insurance premiums and professional fees: expenses you prepay and use by year-end count in 2026, while deposits for future services usually belong to the year the service is delivered. Keep the 'paid or incurred in 2026' test in mind for every December invoice.

3. Do a Deduction Review While There Is Still Time

Run your books against a full deduction checklist before the year closes: home office (or set up the simplified $5-per-square-foot method for your qualifying space), business mileage, software and subscriptions, marketing, insurance, professional fees and the business percentage of phone and internet. Find missing expenses now, while you can still correct invoices and records, rather than in April when it is too late to change what happened in December.

4. Review Your Quarterly Tax Position and the January 15 Payment

The last estimated tax installment for 2026 income is due January 15, 2027. Before year-end, compare what you have paid against the two penalty-safe benchmarks—90% of your expected 2026 tax or 100%/110% of your 2025 tax. If you are behind, the December window is the time to plan the January payment so you walk into the new year penalty-free rather than catching up under interest.

5. Health Insurance, Retirement and Your Own Payroll

If you pay your own health insurance, those premiums are deductible above the line for self-employed people. If you made estimated payments that turn out higher than your actual 2026 tax, you will reconcile it at filing—overpaying is simply an interest-free loan to the IRS, so use the estimator to tighten the final installment. And if you run an S-corporation, confirm you paid yourself a reasonable salary for 2026 before the year ends; failing the reasonable-compensation test is one of the most common small-business tax mistakes.

6. Close the Books and Set Aside the Final Slice

Before the holiday rush, reconcile your income and expenses, chase unpaid invoices and make your final 2026 set-aside transfer into your tax account. Knowing your real profit for the year lets you decide the last deductible purchases and the exact January payment with confidence—and keeps the January 15 and April deadlines from colliding with your filing stress.