Most small businesses build next year's budget in December — between holiday orders, year-end closing, and the general exhaustion of Q4. The result is predictable: last year's numbers plus 3%, approved in a hurry, filed in a drawer, and never consulted again after February.
The businesses that actually run on their budgets build them in September. Not because September is calm — because September still has runway. There are four months left to act on what the planning reveals: renegotiate the renewal, make the equipment decision, set up the retirement plan, and have the pricing conversation with customers before the new year makes it awkward. A December budget can only record decisions. A September budget can still make them.
Here is the September play, in five moves.
Move 1 — Reforecast 2026 before you touch 2027
You have eight months of actuals. Before projecting anything, answer the only question that makes a 2027 budget honest: where is 2026 actually landing? Take your January budget (if one exists), lay this year's actuals against it, and study the five biggest gaps — revenue lines that over- or under-delivered, costs that ran hot, the quiet line that doubled. Those variances are the most valuable planning data you own, because they're evidence about your business, not assumptions. A 2027 budget built on the reforecast inherits reality; one built on last January's budget inherits last January's guesses.
Move 2 — Price the increases you already know are coming
Some 2027 costs are not projections — they're announcements. The biggest one this cycle: health insurance. Insurers across all 50 states have filed for a median 14% premium increase in the 2027 small-group market — with 59% of carriers proposing hikes between 10% and 20%, and the underlying medical cost trend running at 10.8% (KFF / Peterson analysis of 295 insurer filings, August 2026). Regulators will trim some filings, and your renewal is your own — but budgeting a low-single-digit benefits increase against that backdrop is planning by hope.
The September advantage: renewal season hasn't peaked. Start the conversation with your broker now — shop competing carriers, price level-funded alternatives side-by-side with fully insured (the migration to level funding is itself reshaping the market), and consider defined-dollar contributions, which make your cost predictable even when premiums aren't. The same discipline applies to your other known increases: wage expectations you've already set, lease escalators, and vendor contracts renewing in Q1. Pull them into the budget as facts, not padding.
Move 3 — Build on drivers, not last year plus 3%
A percentage-increase budget encodes one assumption: next year is this year, slightly inflated. A driver-based budget encodes how your business actually works: customers × average sale for revenue; headcount plan × loaded cost for people; per-employee amounts for the costs that scale with the team. It takes one more evening than the +3% version and produces something fundamentally different — a budget you can interrogate mid-year ("volume is fine, price is the problem") instead of one that just tells you you're over.
If you'd rather not build the machinery yourself, our Rolling Budget & Forecast Model puts this method in a workbook — driver-based budget, monthly actuals, and a rolling reforecast that updates with one cell. The people line comes from its companion, the Headcount Planning Template, which turns salaries into true loaded costs (payroll taxes and benefits included) by month.
While you're in there, zero-base exactly one line: software subscriptions. Companies under 200 employees now average around 40 SaaS apps with roughly half of paid licenses sitting idle. List every subscription; every one either re-justifies itself or dies in the 2027 budget.
Move 4 — Use the fall for tax positioning
This is where September runway turns into money — and where 2026 planning genuinely changed. Under the One Big Beautiful Bill Act, 100% bonus depreciation is now permanent, and the Section 179 expensing limit sits at $2.56 million for 2026 (Rev. Proc. 2025-32; planning guides). The practical shift: the old December panic-buy — "purchase equipment before the deduction shrinks!" — is dead. Equipment timing is now about income placement: if 2026 is a strong year, placing a planned purchase in service before December 31 deducts it against high-bracket income; if 2027 looks stronger, waiting may be worth more. That's a genuine decision, and it needs the Move-1 reforecast to make it.
Three more fall items with real deadlines: retirement plans — a solo 401(k) or safe-harbor plan for 2026 generally needs action well before year-end, and it's simultaneously a tax move and the benefits answer to Move 2's premium problem; S-corporation owners — review your reasonable-salary position before the final payroll of the year, while it's still adjustable; and a small gift for January: the reporting threshold for Form 1099-NEC and most 1099-MISC payments — the forms you issue to contractors and vendors — rises from $600 to $2,000 for payments made in 2026, meaning fewer forms in your January 2027 filing pile. (Don't confuse it with Form 1099-K, the payment-app and marketplace form, which moved the opposite way: its threshold was restored to the old $20,000-and-200-transactions rule — though several states still apply lower thresholds of their own.)
These are planning prompts, not tax advice — run your specifics past your CPA in October, when they have time to think, not in March, when they don't.
Move 5 — Put the rhythm on the calendar
A budget consulted quarterly is a decoration. The September play ends by scheduling 2027's operating rhythm before 2027 starts: a monthly close with fifteen minutes of budget-versus-actual (the Rolling Budget & Forecast Model's variance tab is built for exactly this quarter-hour); the weekly 20-minute cash review (our 13-Week Cash Flow Tracker is built for exactly this — the budget sets the year's course, the cash forecast catches the weeks); and one honest Q1 checkpoint where the budget gets revised if reality demands it. A revised budget is a working budget. An untouched one is a souvenir.
What done looks like
By December 31: a driver-based 2027 budget that leadership actually argued about; a health renewal that was shopped, not signed under deadline; equipment and retirement decisions made on purpose; and next year's rhythm already on the calendar. That's perhaps three focused evenings and two phone calls, started now — versus the December version, which costs the same hours and buys none of the leverage.
If you want a second set of eyes on the numbers, a fixed-fee Advisory review pressure-tests a 2027 budget in a week — and if the reason the budget never gets built is that the books are always behind, that's the problem to solve first: it's exactly what our Bookkeeping & Back-Office service exists for.
General information, not tax or benefits advice — the depreciation, retirement, and filing items above depend on your facts and state; confirm with your CPA and broker before acting.