The filing deadline is the real end of year-end tax planning. After December 31st, a significant number of positions remain open until the return goes out, and the difference between a company that captures them and one that doesn't is usually not the tax position itself, but whether anyone ran the right review before the return was filed.

The Highest-Impact Tax Positions Still Available Before Filing

These are the positions where timing and the right review most directly affect taxable income. They require looking at what was economically incurred and how assets were treated, not just what the GL shows.

Missing Accruals That Still Qualify Under Section 461

For accrual-basis taxpayers, expenses incurred during the year but not recorded are often still deductible if they meet the all-events test under IRC Section 461. The liability has to have been fixed and determinable by year-end, regardless of whether the invoice arrived or the payment went out. Bonuses paid within 2.5 months after year-end, professional fees for December work, state taxes, utilities, rent, and interest that accrued but weren't booked all qualify.

This is one of the most consistently missed positions in a year-end review because it requires someone to look at what was economically incurred, not just what made it into the GL. The two numbers are rarely the same, and the gap between them is where the deduction lives.

Fixed Assets That Can Still Be Expensed

If equipment or qualifying property was placed in service during the year and capitalized on the books, it may still be eligible for immediate expensing on the return. The Section 179 election is made on the tax return, not at the point of purchase. Bonus depreciation and the de minimis safe harbor work the same way. For companies that have been growing headcount, building out space, or investing in equipment, this is one of the more material opportunities at filing. The books and the return don't have to match. The return should reflect the most favorable treatment available under the law.

Bad Debt Write-Offs That Unlock Immediate Deductions

Uncollectible AR balances that haven't been written off are a deduction sitting on the balance sheet doing nothing. Review the AR aging before filing, identify balances that are genuinely uncollectible, document the worthlessness, and write them off. The deduction is ordinary and immediate. The IRS expects evidence of genuine uncollectibility, not just age. A written record of collection attempts or a specific reason the balance can't be recovered makes the position defensible.

Missed or Unrecorded Expenses That Can Be Recovered

Expenses paid from personal funds, reimbursements that were never processed, credit card charges that didn't make it into the books, small recurring subscriptions miscategorized or missed entirely. These are deductible if substantiated. The threshold for recoverability is documentation, not timing. If the expense was real and the records exist, it belongs on the return.

Inventory Adjustments That Reduce Taxable Income

Obsolete inventory and shrinkage reduce taxable income in the period the impairment is identified, not when the stock is eventually disposed of. If inventory hasn't been reviewed and adjusted before filing, that window is still open. A write-down before the return goes out is cleaner than one reconstructed after the fact, and the tax benefit is immediate.

Tax Elections and Strategic Adjustments That Are Still Open

These positions require more analysis than timing corrections but carry more upside. They're also the ones most likely to be missed entirely because they sit at the intersection of tax strategy and operational structure rather than bookkeeping accuracy.

Retirement Contributions Before the Deadline

SEP-IRA and Solo 401(k) employer contributions are deductible up to the filing deadline including extensions, typically September 15th for S-Corps and partnerships and October 15th at the individual level. The 2024 limit is $69,000 subject to compensation constraints. This is one of the most straightforward remaining levers in year-end tax planning and one of the few that requires action rather than documentation. The contribution has to be funded before the deadline. Electing it without funding it doesn't preserve the deduction.

QBI Optimization Through W-2 Wages and UBIA

The Section 199A deduction of up to 20% of qualified business income is still adjustable before filing for S-Corp owners who haven't yet filed payroll corrections. W-2 wages are one of the primary factors determining QBI eligibility for higher-income taxpayers. Adjusting them before the payroll deadline can unlock or increase the deduction materially. Asset basis under UBIA is the other lever. Neither requires new transactions. Both require analysis of the current structure before the return locks, and the analysis has to happen before the payroll filing window closes independently of the tax return.

State Tax Elections Including PTET

Pass-through entity tax elections remain available in several states on a retroactive or extended basis. Where they apply, they convert a nondeductible personal tax payment into a business deduction with a federal benefit. The rules and election windows vary significantly by state. Missing the PTET election is recoverable in some states and permanent in others, which means it warrants a specific review before filing regardless of where the business operates. The benefit can be material. The window to capture it is state-dependent and not always aligned with the federal filing deadline.

Accounting Method Changes and Section 481(a) Adjustments

A Form 3115 accounting method change is the highest-impact position available on a timely filed return and the most commonly overlooked. It can generate a Section 481(a) adjustment that pulls deductions from prior years into the current return in a single catch-up. For companies that have been applying the wrong method or that are eligible to adopt a more favorable one, the adjustment can be material. The recurring item exception, which allows certain accrued expenses to be deducted even if paid after year-end, is also available through a method change if it wasn't previously elected.

This is not a minor technical fix. The analysis required to identify whether a method change is beneficial and how to structure the 481(a) adjustment doesn't get done cleanly for the first time under filing deadline pressure. It requires a tax advisor who already understands the company's financial position, not one reviewing a snapshot in March.

Documentation-Driven Deductions: What Can Still Be Captured

If it happened and you can prove it, it's still deductible. These positions don't require analysis of accounting method or structural elections. They require someone to find the records before the return goes out.

Owner Health Insurance Premiums Paid Outside the Business

For self-employed individuals and S-Corp owners, health insurance premiums paid personally are an above-the-line deduction that frequently doesn't make it into the return. If the premium was paid outside the business and never recorded, it still belongs on the return. It just needs to be found before filing.

Meals and Travel Expenses Miscategorized or Never Captured

Meals and travel expenses that were miscategorized or never captured are recoverable with proper documentation. Business meals are 50% deductible and the records to support them, dates, attendees, and business purpose, are what the IRS expects. If they exist, the deduction follows.

Charitable Contributions Recorded After the Fact

Charitable contributions made before December 31st that weren't recorded properly can still be reflected on the return if substantiated. For donor-advised fund contributions, the deduction belongs in the year the contribution to the fund was made, not when grants are distributed. If that timing was missed, it's worth confirming before the return is filed.

What Year-End Tax Planning Cannot Fix After December 31st

Cash Basis Expenses Not Paid Before December 31st

Cash-basis expenses not paid before December 31st are not deductible in the prior year. The rule is absolute. An invoice dated December 28th that wasn't paid until January 3rd is a next-year deduction regardless of when the work was done or the bill arrived.

Payroll Timing Decisions Fixed at Year Close

Payroll timing decisions are largely fixed once the year closes. The wages paid, the bonus timing, and the W-2 amounts that flow into QBI calculations were determined by what actually happened in the payroll cycle. Adjusting them after close requires amended payroll filings with their own deadlines and constraints.

Elections That Required Action During the Tax Year

Certain elections explicitly required action during the tax year. The window for those is gone. A review that treats them as potentially recoverable wastes time and creates false confidence that the return is more complete than it is. Knowing which positions are permanently closed is as important as knowing which ones are still open.

Why Most Companies Still Miss These Before Filing

The most common reason is structural, not strategic. Tax gets handed to an external preparer or a compliance-focused advisor who is working from the books as they were closed, not from a review of what was economically incurred. The GL is the starting point and whatever didn't make it in doesn't get found.

The second reason is timing. By the time the return is being prepared, the finance team has moved on to the current year. There's no structured moment where someone asks what was incurred but not recorded, what can be reclassified, or what elections are still available. The review that would catch these positions has no designated owner and no designated window.

The third reason is that tax and accounting operate sequentially rather than simultaneously. The accounting team closes the books. The tax team receives them. By the time the tax team is looking at the numbers, the window to adjust many entries has already closed, and the work required to reconstruct what was missed is more intensive than catching it in the first place would have been. 

The Real Difference: Year-End Scramble vs. Year-Round Alignment

The companies that capture the most available tax value in a given year aren't the ones running the best filing review. They're the ones where tax and accounting are aligned throughout the year so that the filing review confirms what's already been addressed rather than discovering what was missed.

When a tax advisor has live visibility into the books, accrual gaps surface in the period they arise. Fixed asset classifications get reviewed at the point of entry. QBI implications get modeled when compensation decisions are being made, not reconstructed in March. The filing deadline becomes a confirmation point rather than a discovery process.

At PIF Advisory, our tax and accounting teams work from the same live financial data throughout the year. The accrual gaps, capitalization questions, QBI analysis, and method change evaluations are part of a continuous review, not a filing deadline exercise. Where clients come to us at year-end, we run the full pre-filing review and identify what's still recoverable. Where they work with us throughout the year, most of these positions are already addressed before December arrives.

The positions above are recoverable before the filing deadline. The question is whether your current process is built to find them before the window closes.

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