Missed your S‑Corp/Partnership Tax Filing Extension?

It happens: you filed an extension for your S‑corporation or partnership and then life and client work took over. With the September 15 extended federal deadline for calendar‑year S‑corps and partnerships, this question spikes every late summer. Missing it matters because extensions extend time to file, not to pay—and both the IRS and Maryland can assess penalties and interest.

Below are helpful tips to address the situation:

1) Understand what “missed the extension” means

An approved federal extension gives your S‑corp (Form 1120‑S) or partnership (Form 1065) extra time to file, typically to September 15 for calendar‑year filers. If you missed that, the IRS starts counting late‑filing penalties, which for pass‑throughs are assessed per owner, per month, plus separate penalties for late Schedule K‑1s. These penalties can be steep. Interest accrues on any unpaid tax tied to elections like the Maryland pass‑through entity (PTE) tax. Maryland has its own PTE return and payment rules. Bottom line: file and pay as soon as possible to stop the meter.

2) What penalties and issues to expect

Federal late‑filing penalties for S‑corps and partnerships are calculated per shareholder or partner for each month (or part of a month) the return is late, up to a cap. See IRS guidance on penalties for failure to file. There can also be penalties for failing to furnish K‑1s on time. Maryland may assess interest and penalties on unpaid PTE tax or nonresident member tax if applicable. Note that missing the business return can also have other impacts: owners may need their K‑1s to complete their own filings, and banks or licensing boards sometimes request current returns. If you collect sales tax or run payroll, remember those filings are separate—keep those timely to avoid compounding problems.

3) Immediate steps to take this week

File the federal and Maryland returns right away. Start considering penalty relief strategies as well. It is advisable to work with a tax professional who specializes in pass-through-entities to help ensure the tax returns are prepared properly.

4) When to call a professional

If you elected the Maryland PTE tax, have multi‑state activity, late K‑1s to multiple owners, or prior notices, it’s time for professional help. An Enrolled Agent at Aventa Tax can evaluate penalty relief options, prepare accurate late returns, manage IRS and Maryland Comptroller communications, and coordinate owner K‑1 timing. For many service businesses—contractors, law practices, consultants, and medical practices—the cost of a targeted fix is far less than ongoing penalties and lost time.

How Aventa Tax helps local businesses recover and prevent repeats

Aventa Tax provides Maryland small business tax services for S‑corps and partnerships year‑round, so deadlines are planned—not surprises. Our small business accountants in Germantown, Maryland can help you get back into compliance and establish a system to prevent future delays. Further, our advisors can assist with safe‑harbor estimates and PTE tax workflows tailored to your entity. Our business tax preparation services in Montgomery County Maryland include check‑ins before each major deadline so K‑1s and tax returns go out accurately and on time.

Get back on track by speaking with our team at 301-235-2724 or reading more about our business tax filing services.

Disclaimer: This information is for educational purposes only. Please consult a tax professional for specific advice on your situation.