There are two versions of you who deal with taxes. April-you is a hostage: the year is sealed, the numbers are whatever they are, and all that's left is reconstructing twelve months of financial life from receipts and regret. December-you is something else entirely — a person with options. Almost every meaningful tax decision available to a self-employed professional expires at midnight on December 31, which means the weeks before year-end are when your tax bill is actually determined. April just finds out the score.

So this checklist is for December-you, while the options are still alive. Ground rule first, stated plainly: this is general information to organize your thinking, not tax advice. The right answers depend on your entity, your income, your state of affairs — so the goal here is to arrive at your CPA's (virtual) door with better questions, earlier than usual.

Reconcile First — You Can't Optimize a Mystery

Every move below depends on knowing your actual position: what you earned, what you spent, what category it lands in. If the books have drifted since summer — and for most solo practitioners, they have — the reconciliation is the first tax move. Do it in December and the year is still fresh enough to reconstruct accurately; every stray receipt you categorize now is a deduction that survives. Do it in April and you're carbon-dating your own bank statements while a filing deadline breathes on you.

There's a second payoff: December numbers are decision-grade. Whether it's worth accelerating an expense, making a purchase, or funding a retirement account all hinges on what kind of year you actually had — information you can only act on while the year is still open.

Get Your Workspace Story Straight

Your workspace is probably one of your larger deductible categories, and it's also the one where sloppiness costs the most. Two clean scenarios, one common mess:

  • Clean scenario one — the true home office. If part of your home is used regularly and exclusively for the business, a home-office deduction may apply. The famous word is "exclusively," and it means what it says — the guest room with a desk in it is a harder story than a room that is genuinely, only, your office. If you claim it, document it like you expect to explain it: what space, what share of the home, used how.
  • Clean scenario two — paid workspace. Rent for an office, a virtual office and business address, meeting rooms booked by the hour, day-office fees — these are ordinary business expenses of the most straightforward kind. The only failure mode is forgetting to capture them all, especially the small, irregular bookings scattered across the year. Pull the year's invoices now and total them; it's usually more than people remember. (We've covered what you can claim on a virtual office in more detail.)
  • The mess — a bit of both, documented as neither. Worked from the kitchen sometimes, rented rooms sometimes, claimed whatever felt right in April. December is when you turn that into a coherent, documented position — with your CPA's help on which parts qualify.

Time Your Purchases Like They Matter (They Do)

If the business genuinely needs equipment — a computer, furnishings, tools of the trade — the calendar becomes a lever: qualifying purchases can often be deducted for the year they're placed in service, so December-versus-January is a real decision with real consequences, in either direction depending on your year. Had a strong year? Your CPA may favor buying before the ball drops. Lean year with a better one coming? Waiting may serve you. The only universally bad move is the one made without asking.

And the standing rule: the tax tail never wags the dog. A deduction returns a fraction of what you spend. Buy what the business needs, time it smartly — never buy because December.

Fund Your Future While It Cuts Your Bill

The most satisfying line on this list: self-employed retirement contributions can reduce this year's taxable income while building actual wealth — the rare move where prudence and tax strategy are the same act. The self-employed have access to plan types with meaningful contribution room, but the details are a thicket: limits vary, some plans must be established before year-end even where contributions can follow later, and the right choice depends on your income and structure. This is the item most worth raising with your CPA in December specifically, because some doors close with the year.

Check Your Estimated-Tax Position Before It Checks You

No employer withheld anything for you this year — staying square was your job, quarter by quarter. December is the moment to compare what you've actually paid against what this year's income implies you'll owe. A shortfall discovered now is manageable: options exist before and at year-end to soften it. The same shortfall discovered in April arrives with penalties attached and zero options. Five minutes with your payment records now buys you out of the worst version of spring.

Leave a Paper Trail Worthy of the Deductions

Last, the meta-item: every deduction above is only as strong as its documentation. Receipts gathered, mileage logged, invoices filed, the workspace story written down — organized now, while memory is warm, into whatever your CPA prefers. An undocumented deduction is a bet that nobody ever asks; a documented one is just arithmetic.

One quiet observation from our side of this: members who run their practice through a real business setup — a dedicated business address, workspace billed as workspace, business mail arriving where business happens — consistently describe tax season as boring, which is the highest compliment tax season can receive. That separation is one of the understated things we provide at OSI Offices: when the business has its own K Street address and its own clearly invoiced costs, the line between personal and business draws itself, all year long. December-you and April-you both approve.

Want next year's books to separate themselves? See how a dedicated business address works at OSI — clean lines for the business, boring Aprils for you.