The S-Corp election is one of the most powerful tax moves available to small business owners. By electing S-Corp status, you can significantly reduce self-employment taxes on your business income — often saving $5,000 to $20,000+ per year depending on your profits.
But there's a catch: the election has a strict deadline, and missing it means waiting another full year to get the benefits. Or does it? Let's break down exactly how the timeline works, what happens if you miss it, and your options for late relief.
The Standard Deadline: March 15
If you have an existing LLC or corporation and want S-Corp tax treatment for the current tax year, you must file Form 2553 (Election by a Small Business Corporation) by March 15 of that year.
For example, to be treated as an S-Corp for tax year 2026, your Form 2553 must be filed by March 15, 2026. Miss that date, and the election won't take effect until January 1, 2027 — meaning you've lost an entire year of tax savings.
This deadline applies to:
- Existing LLCs electing S-Corp status for the first time
- Existing C-Corporations converting to S-Corp status
- Any entity that wants the election effective for the current calendar year
The 75-Day Rule for New Entities
If you're forming a brand new entity, you have a slightly different window. You can file Form 2553 within 75 days of the entity's formation date (or the date you begin doing business, whichever is earlier) to have the S-Corp election apply from day one.
This 75-day window is generous — but it sneaks up fast. If you formed your LLC on January 10, your deadline is March 26. If you formed on November 1, your deadline is January 15 of the following year.
Miss this window for a new entity, and you default to the March 15 rule for the following year. That means your first year (or partial year) will be taxed as a disregarded entity (single-member LLC) or partnership (multi-member LLC).
Form 2553: What You're Actually Filing
Form 2553 is a two-page IRS form, but don't let its simplicity fool you — errors are common and can delay or invalidate your election. Here's what you need to get right:
- Entity name and EIN — must match exactly what's on file with the IRS
- Effective date — the tax year you want the election to begin
- Shareholder consent — every shareholder (or LLC member) must sign and provide their SSN/EIN, ownership percentage, and the date they acquired their shares
- Tax year election — most S-Corps use a calendar year; if you want a fiscal year, you'll need to complete Section Q
Common mistakes that cause problems:
- Missing a shareholder's signature (all must sign)
- Filing with the wrong service center
- EIN doesn't match IRS records (common if you recently changed your entity name)
- Not filing the corresponding state election (South Carolina requires a separate state-level S-Corp election)
What Happens If You Miss the Deadline
If you miss March 15 (or the 75-day window for new entities), the default outcome is straightforward: your S-Corp election will be effective starting January 1 of the following year.
For the current year, your entity will be taxed under its default classification:
- Single-member LLC: disregarded entity (reported on Schedule C)
- Multi-member LLC: partnership (Form 1065)
- Corporation: C-Corporation (Form 1120, double taxation)
The financial impact of missing the deadline varies. If you're a profitable LLC owner making $150,000+, a one-year delay in S-Corp status could cost you $8,000 to $15,000 in unnecessary self-employment taxes. That's real money.
Late Election Relief: Rev Proc 2013-30
Here's the good news: the IRS offers late election relief under Revenue Procedure 2013-30. If you qualify, you can file a late Form 2553 and have the S-Corp election applied retroactively to the beginning of the year (or the entity's formation date).
To qualify for late relief, you must meet ALL of these criteria:
- The entity intended to be classified as an S-Corp as of the intended effective date
- The only reason for the late filing was that Form 2553 wasn't filed timely
- The entity has reasonable cause for the late filing
- The entity and all shareholders reported their income consistent with S-Corp status for the year
- The request is filed within 3 years and 75 days of the intended effective date
In practice, the IRS is relatively lenient with late relief — especially for small businesses that clearly intended to be S-Corps and simply missed the filing. You'll write a statement explaining the reasonable cause ("we were unaware of the deadline" or "our accountant failed to file timely" both work) and attach it to Form 2553.
We've successfully filed late elections for dozens of clients. It's not guaranteed, but the approval rate is high when you meet the criteria.
South Carolina State Election
Don't forget: South Carolina requires a separate state-level S-Corp election. You must file Form SC1120S with the SC Department of Revenue. The state generally follows the federal election date, but filing the federal form alone is not sufficient for state purposes.
If you're operating in South Carolina and elect S-Corp status federally, make sure your CPA files both elections simultaneously.
Is S-Corp Right for You?
The S-Corp election isn't right for everyone. It adds complexity — you'll need to run payroll, file a separate business return (Form 1120S), and set a "reasonable salary" that can withstand IRS scrutiny.
Generally, S-Corp makes sense when your net business income exceeds $50,000 to $60,000 after paying yourself a reasonable salary. Below that threshold, the payroll costs and additional filing complexity may outweigh the tax savings.
We go deep on this decision in our article on when to switch your LLC to an S-Corp. And if you have rental properties in the mix, the analysis gets more nuanced — check out our comparison of LLC vs S-Corp for rental properties.
Don't Let a Deadline Cost You Thousands
The S-Corp election deadline is one of those things that seems minor until you miss it. If you're considering the switch — or if you've already missed the deadline and need help with late relief — reach out to Beacon Accounting. We'll evaluate whether S-Corp status makes sense for your situation and handle the filing so you don't have to worry about it.