2026 year-end tax planning: update the forecast before buying deductions

Many small-business owners treat late fourth-quarter spending as an automatic way to reduce taxes. In practice, a year-end purchase only changes a 2026 tax calculation if the underlying profit forecast is current, the expenditure qualifies under the applicable rules, and the business can afford the cash outlay.

Before buying equipment, vehicles, or prepaid items to lower a projected tax bill, update the year-to-date books and build a written 2026 projection that connects business profit, owner compensation, and cash flow.

Start with reconciled books rather than a bank balance

A checking account balance in October or November does not show taxable income. Loan proceeds, owner transfers, customer deposits, unrecorded bills, and sales tax collected can make cash look higher or lower than actual profit.

Reconcile business checking, savings, credit card, and payment-processor accounts through the latest completed month first. Our monthly bookkeeping close checklist for Houston businesses walks through that sequence step by step. Once the historical months are reconciled, estimate revenue and ordinary operating expenses for the remaining weeks of the year.

Model how 2026 deduction rules interact with your profit

Even when a business purchase is ordinary and necessary, how and when it reduces taxable income depends on specific statutory tests:

• Section 179 expensing (Rev. Proc. 2025-32): For tax years beginning in 2026, the IRS inflation procedure lists a maximum Section 179 deduction of $2,560,000, reduced once qualifying property placed in service exceeds $4,090,000, with a $32,000 Section 179 cap for certain sport utility vehicles. Section 179 is also subject to a taxable-income limitation from active trades or businesses; see our 2026 Section 179 limits guide and IRS Revenue Procedure 2025-32.
• 100% additional first-year depreciation (Notice 2026-11): Treasury and the IRS issued guidance on the restored 100% bonus depreciation deduction for eligible property acquired and placed in service after January 19, 2025; see the IRS Notice 2026-11 announcement and our 2026 bonus depreciation guide.
• Placed-in-service timing (Publication 946): Paying for equipment before December 31 is not the entire test. Depreciation and Section 179 generally begin when property is placed in a condition or state of readiness and availability for a specifically assigned function; see IRS Publication 946 and our placed-in-service evidence checklist.

Compare the tax reduction to the real cash cost

Spending $40,000 on equipment you do not operationally need does not save $40,000 in cash. If an expenditure reduces taxable income at a combined marginal rate of, for example, 24%, the illustrative federal tax reduction is $9,600 while the business still parts with $40,000 in cash or takes on $40,000 in debt.

Review three questions before approving a year-end purchase:

1. Does the business need this asset or expense to serve customers, improve reliability, or replace worn equipment in the next 12 months?
2. Will the property actually be delivered, installed, and ready for business use on or before December 31, 2026?
3. How does the deduction affect other items on the return, such as 2026 QBI deduction calculations, S-corporation shareholder basis, or future loan underwriting?

Build a simple before-and-after projection

Ask your accountant to compare two columns using your reconciled numbers: your projected 2026 tax position with no extra year-end purchases, and your projected position with the proposed purchase or retirement contribution included. Keep the invoice, delivery documentation, financing agreement, and placed-in-service records together in your year-end tax file.

Tax N Tips provides Houston tax planning, monthly bookkeeping, and individual and business tax preparation for clients across Greater Houston and nationwide. Book a free consultation to update your 2026 projection before year-end.

Sources checked October 30, 2026: IRS Revenue Procedure 2025-32 / IRB 2025-45, Notice 2026-11 announcement, and Publication 946.