The 12-Month Tax Planning Calendar for Business Owners (What Actually Happens Each Quarter)

Executive Summary

Tax planning is a year-round sport for business owners, and we are entering the most important stretch of the year.  If you treat tax planning as a problem for April, you are missing out!

Tax planning is a twelve-month program with six real decision points across the year.  Here is what each quarter actually requires, and the decisions we work through with business owners at each stage.

Three points worth stating up front, because they drive most of what follows:

1. Business performance is the main lever that makes this hard. When a business takes off and generates substantial profits, taxes must keep up too.  
2. You cannot plan on books you cannot understand. If your bookkeeping is weeks or months behind or your expense coding is unreliable, every projection built on it is guesswork. Clean books are a tax planning necessity.
3. Safe harbor is a penalty number, not a planning number. Paying enough to avoid an IRS penalty tells you nothing about what you will actually owe. These are two separate calculations and confusing them is the most common mistake we see.

Why Tax Planning for Business Owners Works on a Calendar

An employee has one meaningful tax decision each year, which is how much to withhold. A business owner has closer to a dozen, and most of them are time sensitive.

You choose your own salary. You decide when to buy equipment. You decide whether to fund a retirement plan, and how much. You decide when to recognize income and when to defer it. You decide whether to accelerate charitable giving. Each of those choices has a deadline, and several of them cannot be fixed after December 31.

The owners who pay the least tax over the long term are not the ones with the most aggressive strategies. They are the ones who deliberately plan ahead.

Quarter 1: January Through March

What is due

January 15. The fourth quarter estimated tax payment for the prior year is due. 

January 31. W-2s go to employees and 1099s go to contractors.

March 16, 2026. Pass-through returns are due for S Corporations and Partnerships. The statutory due date is March 15, but it moved to Monday, March 16 in 2026 because March 15 fell on a Sunday. Filing an extension before the deadline provides an additional six months to file before September 15.

What to decide

Whether to extend. Extending is not a red flag, and it is not a delay tactic. It is often the right call when a K-1 is outstanding, when retirement plan contributions are still being calculated, or when the books need cleanup. What an extension does not do is extend your time to pay.

Whether the January payment can be skipped. If your business had a weak fourth quarter, or if you are carrying an overpayment forward from the prior year, the January estimate may be unnecessary. This requires a tax projection, not a guess.

Whether last year's structure still fits. Q1 is when the prior year is fresh and the current year is still open. It is the easiest time to change an entity election, adjust an owner compensation approach, or fix a payroll practice. If you are questioning whether your current entity is still the right one, we walk through the tradeoffs in choosing the right structure for your business.

Quarter 2: April Through June

What is due

April 15. Individual returns are due, along with the first estimated tax payment for the current year.

May 15. The Texas franchise tax report is due. For the 2026 report year, entities with annualized total revenue at or below $2,650,000 owe no franchise tax. Entities under the threshold still have to file a Public Information Report or Ownership Information Report.

June 15. The second estimated tax payment is due. Note that the IRS calendar is uneven. The second payment covers only April and May, which is two months, not three.

What to decide

Your safe harbor number, separate from what you will actually owe. Here is why owners get tripped up: If you had a low income year followed by a strong one, your safe harbor number can be small while your actual liability is large. Hitting safe harbor means no penalty if paid before April 15.

It does not mean you are done paying. We have seen owners treat a small safe harbor figure as good news and then face a substantial April balance with no cash set aside.

High earning owners have two additional traps worth understanding, which we cover in the two tax torpedoes high-earning owners must watch out for.

Quarter 3: July Through September

This is the most important quarter of the year for business owners, and the one most often overlooked.

What is due

September 15. Three things land on this date at once.

The third estimated tax payment is due. Extended S Corp and partnerships returns are due. And for many owners, retirement plan contributions need to be funded.

If you are still deciding what kind of plan fits your business, our 401(k) plan overview and examples for owners and employees covers how the common structures compare.

What to decide

Refresh the projection with real numbers. After closing the books in September, you have eight months of actual results. This is the first point in the year where a projection is reliable enough to drive decisions.

Set the owner compensation target. For S corporation owners, reasonable compensation is not a fixed number. It scales with the income the business actually produced. A year that nets $100,000 and a year that nets $400,000 support very different salary figures, and the second one usually requires a materially higher W-2.

This is also where owner compensation impacts the qualified business income deduction, and the interaction is not intuitive or easy to see. The 20 percent deduction under Section 199A was made permanent by the 2025 tax law. 

For 2026, the phase-in range for married filing jointly runs from $394,600 to $544,600. We summarized the broader legislation in our overview of the One Big Beautiful Bill Act.

Owner compensation also drives how your health insurance premiums are handled. If you are an S corporation owner, the reporting mechanics matter and are easy to get wrong. Our step-by-step guide to the S-Corp health insurance deduction walks through it.

Below the threshold, a lower salary can increase pass-through income and the deduction, subject to reasonable compensation rules. Above the threshold, the math flips for non-service businesses because the deduction is limited by W-2 wages. For specified service businesses like consulting, law, accounting, and financial services, the deduction phases out above the range regardless of salary.

Confused already? We totally get it and that's why the right software and skillsets are needed to get this right.  

Decide on equipment before you commit. Section 179 expensing for 2026 allows up to $2,560,000, with a dollar-for-dollar phaseout beginning at $4,090,000 of qualifying property. Separately, 100 percent bonus depreciation was restored and made permanent for qualifying property.

The planning point is not whether a deduction exists. It is whether buying is the right business decision, and if so, whether this tax year or next produces the better result. An equipment purchase evaluated inside a full projection is a strategy. The same purchase made in late December because someone mentioned a write-off is usually just spending.

Quarter 4: October Through December

What is due

October 15. Extended individual returns are due.

December 31. A hard deadline for most planning moves. Roth conversions, charitable gifts, equipment placed in service, and additional payroll all have to be complete.

What to decide

Final salary, bonuses, and withholding. If income came in higher than projected, an additional year-end paycheck can correct both the reasonable compensation position and the withholding shortfall in a single step. Monthly payroll is not required for this. For an owner with volatile income, one properly structured year-end paycheck is often the cleanest approach.

Whether the January estimate can be reduced or skipped. With more data and any overpayment carryforward known, this becomes a real calculation.

Retirement plan funding for the current year. The 2026 employee deferral limit is $24,500, with an $8,000 catch-up at age 50 and older, and $11,250 for ages 60 through 63. The total defined contribution limit is $72,000, and the compensation cap used in the calculation is $360,000. SEP contributions follow the lesser of 25 percent of compensation or $72,000 (IRS 2026 limits and IRS COLA table).

Bunching and donor advised funds. If you give consistently but your itemized deductions land near the standard deduction, bunching two or three years of giving into a single year can produce a deduction you would otherwise lose. A donor advised fund lets you take the deduction now and distribute to charities over time. Q4 is when this decision must be made, and it works best when it follows the projection rather than replacing it. There is also a way to combine appreciated securities with this approach, which we explain in double dipping on tax savings for charitable giving.

HSA funding. For 2026 the limits are $4,400 for self-only coverage and $8,750 for family coverage, plus a $1,000 catch-up at age 55 and older. The legal deadline runs to the following April, but we generally recommend funding during the tax year for cleaner tracking, and funding from personal rather than business accounts.

Roth conversions before year end.  If you have a down year in the business and want to move additional funds from pre-tax to post-tax Roth accounts, you must complete this conversion before year end.

Roth conversions before required distributions begin. The window between retirement and the first required minimum distribution year is often the lowest-bracket period of an owner's life. Once required distributions start, that flexibility narrows. Qualified charitable distributions become the more efficient tool at that stage.

Compensation paid to family members. Paying an adult child through the business can shift income from your marginal rate to theirs. This works only when the compensation reflects actual work, at a defensible rate, with documentation. Assigning a defined set of projects rather than vague hourly time is what makes the position supportable.

For a fuller list of what belongs in this quarter, see our favorite year-end tax planning strategies.

How These Decisions Connect

Your salary decision affects five things at once. Payroll taxes, your qualified business income deduction, your retirement plan contribution capacity, your withholding position, and your reasonable compensation exposure. Optimizing for one of those in isolation usually costs you on another.

Equipment purchases affect cash flow before they affect taxes. If a purchase strains working capital during a slow quarter, the deduction has not helped you. We often find a line of credit is the right bridge, so a business can fund a required retirement contribution on time without deferring it.

Bookkeeping quality determines planning accuracy. A large uncategorized expense or a mishandled client reimbursement can distort operating results enough to make a projection useless. When we see recurring coding problems, the right first step is usually mapping the underlying process, meaning how money comes in and how money goes out, rather than replacing the bookkeeper and hoping for a better result.

Personal and business decisions are the same decision. Education funding, estate documents, insurance coverage, and charitable giving all move when business income moves. Owners who keep their business advisor and their personal advisor separate end up coordinating that themselves, usually in December.

Today's decisions shape your eventual exit. Clean books, documented compensation, and a defensible expense history are exactly what a buyer will examine. Owners are often surprised by what matters most, which we address in the number one thing business owners forget to check before selling.

A Simple Calendar You Can Use

What We Do Differently

We handle tax planning for business owners alongside tax preparation, investment management, and business consulting on one team. That is not a service list. It changes what is possible.

When the same team prepares the return, runs the projection, manages the portfolio, and reviews the business financials, the September projection is built on numbers we already understand. The salary recommendation accounts for the retirement plan and the portfolio. The equipment decision accounts for practice cash flow. Nobody has to reconcile conflicting advice from three firms in December.

Most owners we work with previously had a CPA who filed returns, an advisor who managed investments, and nobody responsible for connecting the two. The gap between those roles is where the planning opportunities live. You can read more about our tax planning and preparation approach for business owners, how we work with owner-operated B2B service firms, or our process for new client relationships.

Frequently Asked Questions

Is hitting safe harbor enough?

It prevents an underpayment penalty but does not tell you what you owe. If your income rose meaningfully from the prior year, you can satisfy safe harbor and still face a large balance in April. Both numbers need to be calculated.

Do I need monthly payroll as an S corporation owner?

No. What matters is that total compensation for the year is reasonable relative to the income the business produced. For owners with uneven income, a single properly structured year-end paycheck can work well.

Does Texas having no income tax make tax planning less important?

It makes federal planning more important. Without a state income tax offset, federal timing decisions carry the full weight of the outcome.

Can I keep my current CPA and use you only for planning?

We generally prefer to handle both. When tax preparation and tax planning sit in different firms, recommendations get implemented inconsistently or not at all. Coordinating around another firm's differing positions tends to reduce the value of the planning.

Next Step

If you are a business owner and your tax conversations happen once a year at filing time, you are likely opportunities on the table.

We would be glad to walk through your current situation and show you what a full-year calendar would look like for your business.

Written by Kyle Simmons, CFP®, a financial planner and shareholder at J.E. Simmons and Company. J.E. Simmons and Company is a fee-only registered investment adviser serving business owners from Dallas, Texas. This article is general information, not tax or investment advice for any specific situation. Tax rules change and apply differently depending on facts. Figures cited are for the 2026 tax year. Please consult a qualified financial planner or tax professional before acting.

Disclosure

The content and information presented herein are for educational purposes only and should not be construed as a solicitation or offer to buy or sell any investment services. Nothing contained in this material should be considered an offer to provide any product or service in any jurisdiction that would be unlawful under the securities laws of that jurisdiction. The information contained herein has been obtained from sources believed to be reliable; however, the Firm does not guarantee accuracy or completeness of the information. Such information is subject to change at any time without notice. Before taking any action, you should consult with a qualified tax, legal, or financial professional.