If you operate an S-Corporation and missed the calendar-year tax deadline of March 16, 2026, you are likely facing significant IRS penalties.
The Exact 2026 Late Filing Penalties for Form 1120-S
The IRS calculates late penalties for S-Corporations based on the number of shareholders and how long the return is delayed:
- The Failure-to-File Penalty: For returns due in 2026, the IRS assesses a late filing penalty of $255 per shareholder, per month (or partial month), for up to 12 months.
- The K-1 Penalty: Failing to provide shareholders with correct Schedule K-1s on time typically results in an additional penalty of about $310 per form.
A Real-World Example: If a five-shareholder S-Corp files just one month late, the penalty calculation is $255 multiplied by 5 shareholders, multiplied by 1 month, resulting in a sudden $1,275 penalty.
How to Fix It: IRS Penalty Relief
The IRS First-Time Penalty Abatement is an administrative waiver that can relieve you from failure-to-file and failure-to-pay penalties. To qualify, you generally must have a clean compliance history of filing and paying on time.