September 2, 2026
September 15 Isn’t Just a Filing Deadline—It’s a Tax Planning Opportunity
September 15 Isn’t Just a Filing Deadline—It’s a Tax Planning Opportunity
For many business owners, September 15 marks an important tax deadline. Calendar-year partnerships and S corporations that requested an extension generally have until September 15 to file their federal income tax returns.
But completing the return shouldn't necessarily be the end of the tax conversation.
By September, your business will have eight months of financial results available, making this an excellent time to shift the focus from reporting what happened last year to planning for what will happen this year.
What the September 15 Deadline Means
Partnerships and S corporations are generally considered "pass-through" entities. Rather than paying federal income tax at the entity level, income and certain other tax items pass through to the owners and are reported on their individual income tax returns.
Once these returns are completed, owners receive Schedule K-1 reporting their share of the entity's income, deductions, credits, and other tax information.
For business owners who extended their individual returns, receiving the K-1 is often one of the final pieces needed to complete their personal tax returns.
Don't Stop With Last Year's Tax Return
A completed business tax return provides valuable historical information, but by September, the more important question may be:
What is happening this year?
Business conditions can change significantly from one year to the next. Revenue may be higher or lower than expected. The business may have purchased equipment, hired employees, taken on debt, sold assets, or made significant distributions to owners.
Those changes can have a meaningful impact on an owner's tax situation.
Instead of waiting until tax preparation begins next year, September provides an opportunity to estimate where the business finish the year and identify planning strategies to achieve better outcomes.
Questions Business Owners Should Be Asking
With several months remaining in the year, consider discussing questions such as:
- How does this year's income compare with last year?
If profitability has increased significantly, owners may need to adjust estimated tax payments or prepare for a larger tax liability.
- Are estimated tax payments still appropriate?
Estimates calculated earlier in the year may no longer reflect current business results. Reviewing projections can help reduce the risk of a large unexpected balance due.
- Are there significant purchases or investments planned before year-end?
Equipment, vehicles, real estate improvements, and other capital expenditures can have tax implications. The timing and structure of these purchases can matter.
- Are owner compensation and distributions being handled appropriately?
For S corporation owners in particular, reasonable compensation continues to be an important consideration. Significant changes in business profitability may warrant another look at compensation before year-end.
- Have there been major changes in the business?
New owners, ownership changes, significant loans, property transactions, expansions, or other unusual events should be discussed with your tax advisor before year-end whenever possible.
- Are there retirement planning opportunities?
Depending on the business and retirement plan, there may still be opportunities to evaluate contributions or plan design before the end of the year.
Schedule Your Tax Planning Appointment before Year End
When we review a business's tax situation before year-end, there may still be time to evaluate alternatives, make adjustments, and understand the tax consequences of business decisions before they become final.
Not every business needs to make a year-end tax move. Sometimes the most valuable outcome of planning is simply knowing what to expect.
A projection can help business owners understand their anticipated taxable income, evaluate estimated payments, plan for cash needs, and avoid surprises when tax returns are prepared.
If your partnership or S corporation filed an extension, completing the return by September 15 is important, but don't let the conversation end there.
Talk with our team at Welgaard about whether a year-end planning meeting makes sense for you and your business.