A Sacramento S Corp owner walked into our office last spring convinced she needed to switch to a C Corp because her attorney told her it would “simplify things.” She was 11 days away from filing Form 1120 instead of Form 1120-S and locking herself into a $197,000 five-year tax increase she could never undo. That conversation saved her business. This guide will show you exactly how to change from S Corp to C Corp the right way, why you almost certainly should not do it, and what California business owners need to know before touching that revocation letter.

Quick Answer

To change from an S Corp to a C Corp, you file a revocation statement with the IRS under IRC Section 1362(d)(1), signed by shareholders holding more than 50% of outstanding shares. If filed by March 15, the change takes effect January 1 of the current year. If filed after March 15, it takes effect January 1 of the following year. California requires a separate notification to the Franchise Tax Board. But here is what matters most: this switch triggers double taxation, kills your QBI deduction, eliminates your AB 150 PTE election, and locks you out of re-electing S Corp status for five full years under IRC Section 1362(g). For a business earning $200,000 in annual profit, that is a $39,400 per year tax increase.

How to Change From S Corp to C Corp: The Actual IRS Process

The IRS does not have a dedicated form for revoking your S election. Instead, you submit a written revocation statement to the IRS Service Center where you file your annual return. That statement must include your company name, EIN, the date the revocation should take effect, and a declaration that shareholders owning more than 50% of shares consent to the revocation. Each consenting shareholder must sign, and you must attach a statement of the number of shares each shareholder owns on the date the revocation is filed.

Critical Filing Deadlines

The deadline that controls everything is March 15. If you mail the revocation statement by March 15 of the current tax year, the revocation is effective January 1 of that same year. Miss that date by even one day, and your revocation does not kick in until January 1 of the next tax year.

You can also choose a prospective effective date. For example, you could file a revocation on June 1 and specify that the revocation becomes effective July 1. In that scenario, you file a short-year S Corp return (Form 1120-S) for January 1 through June 30 and a short-year C Corp return (Form 1120) for July 1 through December 31. This split-year filing under IRC Section 1362(e) is complex and requires careful allocation of income, deductions, and credits between the two periods.

California FTB Notification

California does not automatically follow your federal revocation. You must separately notify the Franchise Tax Board by filing the appropriate documentation with your Form 100 (California Corporation Franchise or Income Tax Return). Fail to do this, and California may continue treating you as an S Corp while the IRS treats you as a C Corp, creating a compliance nightmare that can trigger penalties from both agencies.

This information is current as of April 20, 2026. Tax laws change frequently. Verify updates with the IRS or FTB if reading this later.

The Five-Layer Tax Increase You Are Walking Into

Most business owners who ask how to change from S Corp to C Corp do not realize they are volunteering for five simultaneous tax increases. Here is the math at $200,000 in annual business profit.

Layer 1: Federal Corporate Tax (21%)

As an S Corp, your business profit passes through to your personal return and is taxed once. As a C Corp, the business pays 21% federal corporate tax on every dollar of profit before you see a dime. On $200,000, that is $42,000 in corporate-level tax that did not exist before.

Layer 2: Federal Dividend Tax (15% to 23.8%)

After the corporation pays its 21% tax, you still need to get the remaining $158,000 into your pocket. When you take it as a dividend, you pay an additional 15% to 23.8% in federal tax (including the 3.8% Net Investment Income Tax for higher earners). That is another $23,700 to $37,604 in tax on money that already got taxed once. This is the double taxation trap that makes C Corps expensive for owner-operated businesses.

Layer 3: California Franchise Tax Swing

California charges S Corps a 1.5% franchise tax on net income (minimum $800). C Corps pay 8.84%. On $200,000, your California franchise tax jumps from $3,000 to $17,680. That is a $14,680 annual increase from one state alone.

Layer 4: QBI Deduction Loss

The Qualified Business Income deduction under IRC Section 199A, made permanent by the One Big Beautiful Bill Act (OBBBA), allows S Corp shareholders to deduct up to 20% of their qualified business income. On $200,000, that deduction could be worth $40,000, saving you $8,800 to $14,800 depending on your marginal rate. C Corp shareholders get zero QBI deduction. It simply does not apply to C Corporations.

Layer 5: AB 150 PTE Election Elimination

California’s AB 150 Pass-Through Entity tax election allows S Corp owners to pay state income tax at the entity level and claim a corresponding federal deduction, effectively bypassing the $40,000 SALT cap (raised from $10,000 by OBBBA). C Corps cannot use this election. For a California S Corp owner in a high tax bracket, this costs another $3,000 to $8,000 per year in lost federal savings.

Key Takeaway: At $200,000 in profit, switching from S Corp to C Corp increases your total tax burden by approximately $39,400 per year. Over five years, that is $197,000 you cannot recover.

Want to see exactly how your business profit would be taxed under each structure? Run your numbers through this small business tax calculator to compare your take-home under both entities.

The Five Costliest Mistakes When Revoking Your S Election

If you are still determined to learn how to change from S Corp to C Corp, at least avoid these five errors that cost California business owners thousands of dollars every year.

Mistake 1: Ignoring the AAA Distribution Window

Your Accumulated Adjustments Account (AAA) represents previously taxed S Corp earnings that you can withdraw tax-free. Under IRC Section 1371(e), you have a limited post-termination transition period (PTTP) to distribute your AAA balance without dividend treatment. Miss this window, and every future distribution gets taxed as a C Corp dividend. On a business with $150,000 in accumulated AAA, that missed window costs $22,500 to $35,700 in unnecessary dividend taxes.

Mistake 2: Forgetting the Five-Year Re-Election Lockout

Once you revoke your S election, IRC Section 1362(g) prohibits you from re-electing S Corp status for five full tax years without IRS consent. Getting that consent requires a Private Letter Ruling (PLR) that costs approximately $15,300 in filing fees alone, plus professional preparation costs. If you change your mind in year two, you are stuck paying C Corp rates for three more years.

Mistake 3: Skipping the Five-Year Tax Projection

Too many owners make this decision based on one year of numbers. A proper analysis compares your five-year cumulative tax burden under both structures, factoring in salary optimization, retirement contributions, dividend timing, and California franchise tax. For a deeper look at S Corp mechanics, review our comprehensive S Corp tax strategy guide that breaks down every variable.

Mistake 4: Missing California Dual-Filing Requirements

A mid-year revocation means you file both Form 100S (S Corp) and Form 100 (C Corp) for the same tax year in California. Many business owners (and their preparers) file only one return, triggering late-filing penalties of $210 per shareholder per month. For a two-shareholder company that misses by six months, that is $2,520 in avoidable penalties.

Mistake 5: Not Considering Alternative Solutions

In our experience, 9 out of 10 business owners who want to switch to C Corp are actually trying to solve a problem that has a better solution within the S Corp structure. Want to retain earnings? Set up a Solo 401(k) or defined benefit plan. Need to bring on investors? Restructure ownership within S Corp rules. Think you are overpaying on payroll taxes? Optimize your reasonable salary. The answer is almost never “become a C Corp.”

Pro Tip: Before filing any revocation, request a side-by-side five-year tax projection from a qualified strategist. The $2,000 to $5,000 you spend on that analysis could save you $197,000 or more.

Three Narrow Scenarios Where C Corp Actually Wins

We are not saying C Corp status is always wrong. There are three specific situations where it makes financial sense, and they are narrower than most people think.

Scenario 1: Venture Capital Funding

Most institutional investors and venture capital firms require C Corp status because they need preferred stock classes, which S Corps cannot issue (S Corps are limited to one class of stock under IRC Section 1361(b)(1)(D)). If you are actively pursuing Series A or later-stage funding and have term sheets on the table, converting may be necessary. But confirm with your investors first. Many early-stage deals can work with LLC structures that convert at closing.

Scenario 2: QSBS Section 1202 Exclusion

Qualified Small Business Stock under IRC Section 1202 allows C Corp shareholders to exclude up to $10 million (or 10 times their adjusted basis) in capital gains when they sell stock held for more than five years. The OBBBA expanded this benefit with additional tiers at 50% and 75% exclusion levels, with gains taxed at a 28% capital gains rate under the partial exclusion tiers. If you are building a company specifically to sell it for more than $10 million and plan to hold shares for at least five years, QSBS may justify C Corp status. But you need to satisfy strict requirements including the $50 million gross asset test and active business requirements.

Scenario 3: Full Profit Retention Below $250,000

If your business retains 100% of its profits (zero distributions to shareholders) and those profits stay below $250,000 annually, the flat 21% corporate rate may beat your personal marginal rate. But be careful: the accumulated earnings tax under IRC Section 531 imposes a 20% penalty on earnings retained beyond the reasonable needs of the business. And you still face double taxation whenever you eventually take the money out.

Key Takeaway: Unless you fit squarely into one of these three boxes, revoking your S election costs more than it saves. Period.

KDA Case Study: Elk Grove Consulting Firm Owner Avoids $197,000 Five-Year Tax Trap

Denise ran a management consulting firm in Elk Grove structured as an S Corp with $240,000 in annual profit. Her previous CPA retired, and her new accountant suggested switching to C Corp to “take advantage of the flat 21% rate.” Denise called KDA for a second opinion before filing the revocation.

Our team ran a five-year tax projection comparing both structures. The results were stark. As an S Corp with optimized salary of $85,000, QBI deduction, AB 150 PTE election, and a Solo 401(k) contribution, Denise’s total annual tax burden was approximately $52,400. As a C Corp with the same profit level, her combined corporate and personal tax burden would jump to $91,800 annually, a $39,400 per year increase.

Instead of converting, we restructured Denise’s S Corp strategy. We optimized her reasonable salary to maximize payroll tax savings, activated the AB 150 PTE election to bypass the SALT cap, set up a Solo 401(k) with $23,500 in employee contributions plus $46,000 in employer contributions, and filed amended returns to capture missed QBI deductions from the prior two years.

In her first year with KDA, Denise saved $39,400 compared to what she would have paid as a C Corp. She invested $4,800 in our entity formation and restructuring services. That is an 8.2x first-year ROI. Over five years, the projected savings total $197,000, not counting the additional $12,400 recovered from the amended returns.

Ready to see how we can help you? Explore more success stories on our case studies page to discover proven strategies that have saved our clients thousands in taxes.

OBBBA Permanent Changes That Make S Corp Even More Valuable

The One Big Beautiful Bill Act, signed into law in July 2025, made several previously temporary tax provisions permanent. Every one of these changes widens the gap between S Corp and C Corp tax treatment.

Permanent QBI Deduction

The 20% Qualified Business Income deduction under IRC Section 199A was scheduled to expire after 2025. OBBBA made it permanent. S Corp owners benefit from this deduction indefinitely. C Corp owners never will. At $200,000 in qualified business income, this permanent deduction is worth $8,800 to $14,800 per year in tax savings that C Corp shareholders simply cannot access.

100% Bonus Depreciation Restored

OBBBA restored 100% bonus depreciation retroactively for assets acquired from mid-January 2025 onward. This allows businesses to deduct the full cost of qualifying equipment and property in the year of purchase. Both S Corps and C Corps can claim this, but S Corp owners get the additional benefit of passing the deduction through to their personal returns where it can offset other income. California does not conform to federal bonus depreciation under Revenue and Taxation Code Sections 17250 and 24356, so you must maintain dual depreciation schedules regardless of entity type.

$2.5 Million Section 179 Limit

OBBBA doubled the Section 179 expensing limit from $1.25 million to $2.5 million. This gives S Corp owners even more flexibility to accelerate deductions through their personal returns. California limits Section 179 to $25,000, requiring yet another dual-tracking calculation.

$40,000 SALT Cap

The SALT deduction cap increased from $10,000 to $40,000 under OBBBA. While this helps individual taxpayers somewhat, California S Corp owners who use the AB 150 PTE election can bypass this cap entirely by paying state tax at the entity level. C Corp owners cannot use this bypass, making the effective SALT limitation more painful for C Corp shareholder-employees.

What If You Already Revoked Your S Election?

If you have already filed the revocation and the effective date has passed, you have limited but real options for damage control.

Revocation Rescission

If the revocation was filed but the effective date has not yet arrived, you may be able to rescind the revocation with the consent of all shareholders who originally consented. The IRS has accepted rescissions in certain circumstances, particularly when the revocation was filed in error or based on incorrect advice. Time is critical. Contact a tax professional immediately.

Private Letter Ruling for Early Re-Election

If the five-year lockout under IRC Section 1362(g) is in effect, you can request a Private Letter Ruling from the IRS asking for permission to re-elect S Corp status before the five years expire. The filing fee is approximately $15,300, and professional preparation adds another $5,000 to $10,000. Success is not guaranteed, but the IRS has granted early re-election in cases involving change of ownership, material change in business circumstances, or revocation based on tax advice that proved incorrect.

Optimize While You Wait

If re-election is not possible immediately, focus on minimizing your C Corp tax burden. Maximize deductible salary (the opposite strategy from S Corp optimization), fund retirement plans through the corporation, use Section 199A alternatives where available, and plan the timing of dividends carefully to manage your effective tax rate.

Red Flag Alert: IRS Enforcement Is Getting Smarter

The IRS Palantir SNAP system cross-references entity classification changes against income patterns, distribution histories, and payroll records. If you switch from S Corp to C Corp and your compensation, distributions, and profit patterns do not match what the IRS expects from a legitimate C Corporation, you are more likely to face scrutiny.

Specifically, the IRS looks for owners who convert to C Corp but continue taking distributions as if they were still an S Corp. In a C Corp, those distributions are dividends subject to double taxation. Treating them as returns of capital without proper basis documentation triggers reclassification and penalties. The IRS also watches for unreasonable compensation in the opposite direction. Where S Corp owners sometimes set salary too low, C Corp owner-employees sometimes set salary artificially high to shift income out of the double-taxation layer, which creates its own audit risk.

Frequently Asked Questions

How long does the S Corp to C Corp conversion take?

The revocation itself is effective on the date you specify in your statement, or January 1 of the following year if filed after March 15 without a specified date. The administrative process of filing the statement, notifying California FTB, and adjusting your payroll and accounting systems typically takes 30 to 60 days to complete properly.

Can I change from S Corp to C Corp mid-year?

Yes. You can specify a prospective effective date in your revocation statement. However, this creates split-year filing requirements. You must file a short-year S Corp return and a short-year C Corp return, and you need to allocate income, deductions, and credits between the two periods using either the specific identification method or the pro-rata method under IRC Section 1362(e)(3).

Do I need shareholder approval to revoke the S election?

Yes. Shareholders owning more than 50% of all outstanding shares (both voting and non-voting) must consent to the revocation. Each consenting shareholder must sign the revocation statement and include the number of shares they own and the date of consent.

What happens to my accumulated adjustments account when I convert?

Your AAA balance carries forward into a post-termination transition period. During this window, you can distribute AAA as a tax-free return of previously taxed income. After the PTTP closes, any remaining AAA is frozen and cannot be distributed tax-free. Distributions from that point forward follow C Corp dividend rules under IRC Section 301.

Is there a fee to revoke S Corp status?

The IRS does not charge a filing fee for the revocation statement itself. However, the professional costs to properly execute the conversion, including tax projections, dual-year return preparation, California FTB notification, and payroll restructuring, typically range from $3,000 to $8,000 depending on complexity.

Can I convert back from C Corp to S Corp if I change my mind?

Not immediately. Under IRC Section 1362(g), you must wait five full tax years before re-electing S Corp status, unless you obtain a Private Letter Ruling from the IRS granting early re-election. The PLR costs approximately $15,300 in filing fees alone and takes 6 to 12 months to process with no guarantee of approval.

The IRS Is Not Hiding These Rules. You Just Were Not Taught How to Use Them.

Every S Corp tool, from the salary-distribution split to the QBI deduction to the AB 150 PTE bypass, exists specifically to lower your tax burden legally. Walking away from those tools by converting to a C Corp is like selling your house because the kitchen faucet leaks. Fix the faucet.

Book Your S Corp Strategy Session

If you are seriously considering how to change from S Corp to C Corp, get a five-year tax projection before you file anything. Our strategy team will run the numbers side by side, identify every dollar at stake, and show you whether your S Corp needs a revocation or just a better strategy. Most clients discover they are sitting on $20,000 or more in annual savings they never knew existed. Click here to book your consultation now.