Can I Convert a C Corp to an S Corp? The Short Answer Might Save You $41,000 This Year

Every year, thousands of California C Corporation owners hand over tens of thousands of dollars in avoidable taxes because they never asked one question: can I convert a C Corp to an S Corp? The answer is yes, you absolutely can, and the financial gap between these two structures is not a rounding error. At $200,000 in annual profit, the difference can exceed $41,000 per year across five distinct tax layers. That is not theory. That is money leaving your bank account every single quarter because of an entity election you never filed.

Here is the hard truth. The IRS does not send you a letter suggesting you switch. Your state does not flag you. And most CPAs never bring it up unless you ask. So if you are a California business owner sitting in a C Corp structure, this is the question you should have asked two years ago.

Quick Answer

Yes, you can convert a C Corp to an S Corp by filing IRS Form 2553 (Election by a Small Business Corporation). The deadline is March 15 of the tax year you want the election to take effect, or within 75 days of forming your corporation. If you miss that window, you may still qualify for late election relief under Rev. Proc. 2013-30. In California, you must also file FTB Form 3560 to notify the Franchise Tax Board. The conversion itself costs nothing in filing fees, but the tax savings can reach $17,600 to $64,700 per year depending on your profit level.

Five Tax Layers That Make the C Corp to S Corp Conversion Worth Thousands

The gap between a C Corp and an S Corp is not just about one tax rate. It spans five separate layers that compound against you every year you stay in the wrong structure. Many business owners never see the full picture because their CPA only shows them the federal rate.

Layer 1: Federal Entity Tax (21% vs 0%)

A C Corp pays a flat 21% federal corporate income tax on all profits under IRC Section 11. An S Corp pays zero entity-level federal tax. The income passes through to your personal return. On $200,000 in profit, this single layer creates a $42,000 gap before you even consider what happens next.

Layer 2: Federal Dividend Double Taxation

After your C Corp pays that 21% tax, you still need to get the money out. When you take distributions, those are taxed again as qualified dividends at 15% to 23.8% (including the 3.8% Net Investment Income Tax under IRC Section 1411). On $200,000 in C Corp profit, you pay $42,000 in corporate tax, then roughly $23,700 in dividend tax on the remaining $158,000. Your total federal burden hits $65,700. An S Corp owner paying themselves a $90,000 reasonable salary and taking $110,000 in distributions pays approximately $38,800 in total federal tax. That is a $26,900 federal gap.

Layer 3: California Franchise Tax Differential

California hits C Corps with an 8.84% franchise tax under Revenue and Taxation Code Section 23151. S Corps pay just 1.5% under R&TC Section 23802. On $200,000 in profit, that is $17,680 vs $3,000. The California layer alone costs C Corp owners $14,680 more per year.

Layer 4: QBI Deduction Exclusivity Under IRC Section 199A

The Qualified Business Income (QBI) deduction, a 20% deduction on qualified business income, is available to S Corp shareholders but permanently excluded from C Corp owners. The One Big Beautiful Bill Act (OBBBA) made this deduction permanent in 2025. On $110,000 in S Corp pass-through income, the QBI deduction saves roughly $5,100 in federal taxes. C Corp owners get zero.

Layer 5: AB 150 Pass-Through Entity Tax Election

California’s AB 150 allows S Corps to elect a pass-through entity (PTE) tax that effectively bypasses the $40,000 SALT deduction cap (raised from $10,000 under OBBBA). This gives S Corp owners a dollar-for-dollar state tax credit while deducting the PTE tax at the entity level. C Corp owners cannot use this election. The savings range from $2,000 to $8,000 depending on income.

Side-by-Side Comparison at Three Income Levels

Annual Profit	C Corp Total Tax	S Corp Total Tax	Annual S Corp Advantage
$100,000	$39,650	$22,050	$17,600
$200,000	$80,287	$39,000	$41,287
$350,000	$142,900	$78,200	$64,700

Want to see how your specific numbers shake out? Plug your business profit into this small business tax calculator to estimate the difference between structures.

How to Convert a C Corp to an S Corp: The 8-Step California Process

The conversion process is straightforward on paper, but each step has traps that cost business owners thousands when handled incorrectly. KDA’s entity formation services walk clients through every step, but here is the full roadmap.

Step 1: Verify S Corp Eligibility Under IRC Section 1361(b)

Your corporation must meet these requirements: no more than 100 shareholders, all shareholders must be U.S. citizens or resident aliens (no partnerships, corporations, or nonresident aliens), only one class of stock, and the corporation must be a domestic entity. If you have foreign investors or multiple stock classes, you cannot elect S Corp status.

Step 2: Evaluate Built-In Gains Tax Under IRC Section 1374

When you convert from C Corp to S Corp, any appreciated assets inside the corporation are subject to the Built-In Gains (BIG) tax if sold within five years of the conversion. The BIG tax rate is 21% at the federal level. Calculate the fair market value of all corporate assets on the conversion date and compare to their tax basis. If you have significant unrealized gains, factor this into your timing decision.

Step 3: Calculate and Address Accumulated Earnings and Profits (AE&P)

C Corps accumulate earnings and profits (AE&P) under IRC Section 312. After converting to an S Corp, AE&P does not disappear. Distributions are first treated as coming from your Accumulated Adjustments Account (AAA), but once AAA is exhausted, distributions from AE&P are taxed as dividends under IRC Section 1368(c). The cleanest approach is to distribute all AE&P before or immediately after the conversion. You can also make an AAA bypass election under IRC Section 1368(e)(3) to distribute AE&P first in certain situations.

Step 4: File IRS Form 2553

Form 2553 must be filed by March 15 of the year you want the election to take effect, or within 75 days of the start of the tax year. Every shareholder must sign the form. Mail it to the IRS service center listed in the form instructions, or fax it to the designated number. The IRS will send a confirmation letter (CP261) within 60 days. If you miss the deadline, Rev. Proc. 2013-30 provides late election relief if you can show reasonable cause and file within 3 years and 75 days of the intended effective date.

Step 5: File California FTB Form 3560

California requires separate notification. File FTB Form 3560 (S Corporation Election or Termination/Revocation) with the Franchise Tax Board. California does not automatically honor the federal S Corp election. Missing this step means the FTB treats you as a C Corp at the state level, and you pay the 8.84% franchise tax rate instead of 1.5%.

Step 6: Set Up Payroll with Reasonable Salary

As an S Corp shareholder-employee, you must pay yourself a reasonable salary and run payroll through the EDD. The IRS scrutinizes salary-to-distribution ratios heavily. Use industry salary data from the Bureau of Labor Statistics or comparable sources to justify your salary. If your business profits $200,000 and you pay yourself $90,000, the remaining $110,000 flows through as distributions, which are not subject to the 15.3% self-employment tax.

Step 7: Activate AB 150 PTE Election

File the AB 150 pass-through entity tax election with the FTB by June 15 or the original due date of the return (whichever is earlier). This allows the S Corp to pay state tax at the entity level, giving you a dollar-for-dollar credit on your personal return while deducting the payment at the federal level, effectively bypassing the $40,000 SALT cap.

Step 8: Establish Dual Depreciation Schedules

California does not conform to federal bonus depreciation rules under R&TC Sections 17250 and 24356. You must maintain separate federal and California depreciation schedules for all assets. Federal 100% bonus depreciation (permanent under OBBBA) allows full first-year write-offs. California requires standard MACRS depreciation over the asset’s useful life. Failing to maintain dual schedules triggers errors on both your federal and state returns.

Can I Convert a C Corp to an S Corp If I Missed the March 15 Deadline?

Yes. The IRS provides late election relief under Revenue Procedure 2013-30. You must meet three conditions: the entity intended to classify as an S Corp as of the intended effective date, the entity failed to qualify solely because of a late-filed Form 2553, and the entity has reasonable cause for the late filing. If all conditions are met, you can file Form 2553 with a reasonable cause statement up to 3 years and 75 days after the intended effective date. Attach the statement to the form explaining why the election was late. Common acceptable reasons include reliance on a tax professional who failed to file, or lack of awareness of the filing requirement.

For a complete breakdown of S Corp election timing and strategy, see our comprehensive S Corp tax strategy guide for California.

Five Costliest Mistakes When Converting From C Corp to S Corp

Mistake 1: Ignoring the Built-In Gains Tax ($5,000 to $89,000 Exposure)

If your C Corp holds appreciated real estate, equipment, or inventory, selling those assets within five years of the S Corp election triggers the BIG tax at 21% on the built-in gain. A corporation with $400,000 in appreciated assets could owe $84,000 in BIG tax on top of regular income tax. The fix is simple: get a formal appraisal of all assets on the conversion date to establish your BIG baseline, and avoid selling appreciated assets during the recognition period if possible.

Mistake 2: Leaving AE&P Inside the Corporation

Accumulated earnings and profits from your C Corp years do not vanish when you elect S Corp status. If you take distributions that exceed your AAA balance, the AE&P layer triggers dividend treatment under IRC Section 1368(c)(2). Worse, if your S Corp has AE&P and passive investment income exceeding 25% of gross receipts for three consecutive years, the IRS can terminate your S Corp election entirely under IRC Section 1362(d)(3). Clean out your AE&P through a planned distribution before or immediately after the conversion.

Mistake 3: Skipping the FTB Notification

Filing Form 2553 with the IRS does not automatically notify California. You must separately file FTB Form 3560. If you skip this step, the FTB treats your entity as a C Corp. That means you pay the 8.84% franchise tax instead of 1.5%, you lose AB 150 PTE election eligibility, and you file Form 100 instead of Form 100S. This single oversight can cost $14,000 or more annually at the state level alone.

Mistake 4: Setting an Unreasonable Salary

The IRS won the landmark Watson v. Commissioner case by proving that an S Corp shareholder’s salary was unreasonably low. If you pay yourself $30,000 on $200,000 in profits, you are flagging your return for audit. The IRS uses industry comparables, and the Tax Court looks at factors like services provided, training and experience, and comparable salaries for similar roles. A salary that is too low saves payroll taxes in the short run but triggers reclassification of distributions as wages, plus penalties and interest. Aim for 40% to 60% of net profits as salary, benchmarked against industry data.

Mistake 5: Ignoring California Bonus Depreciation Nonconformity

California does not follow federal bonus depreciation rules under R&TC Sections 17250 and 24356. If you claim 100% bonus depreciation on your federal return and use the same number on your California return, you will trigger a state audit adjustment. Maintain dual depreciation schedules from day one. Your federal depreciation will be higher in year one, but your California depreciation will be spread over the asset’s full recovery period. This creates temporary timing differences that must be tracked through the life of every depreciable asset.

KDA Case Study: Sacramento IT Consulting Firm Saves $43,800 in Year One

David, the sole owner of a Sacramento-based IT consulting firm, had been operating as a C Corp for six years. His annual profit averaged $215,000. His previous CPA never mentioned the S Corp election, and David assumed the 21% corporate rate was the best he could do. When David came to KDA, his tax situation looked like this: $45,150 in federal corporate tax, $19,006 in California franchise tax at 8.84%, and roughly $25,200 in dividend tax when he distributed profits to himself. His total annual tax burden exceeded $89,000.

KDA’s team evaluated his eligibility, calculated his BIG tax exposure (minimal, since his primary assets were computers with low basis), distributed his $38,000 in accumulated AE&P before the conversion, and filed Form 2553 with the IRS and Form 3560 with the FTB. They set his reasonable salary at $95,000 based on Bureau of Labor Statistics data for IT consulting managers in the Sacramento MSA, activated the AB 150 PTE election, and established dual depreciation schedules for his equipment.

After the conversion, David’s total tax dropped to $45,200. That is a $43,800 first-year savings. KDA’s fee for the full conversion, payroll setup, and ongoing advisory was $5,800, delivering a 7.6x first-year ROI. Over five years, David’s projected savings exceed $219,000.

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 Changes That Make the C Corp to S Corp Conversion Even More Valuable in 2026

The One Big Beautiful Bill Act, signed into law in July 2025, made several provisions permanent that dramatically increase the S Corp advantage over C Corps.

Permanent QBI Deduction Under IRC Section 199A

The 20% QBI deduction was set to expire after 2025 under the original TCJA. OBBBA made it permanent. This means S Corp owners can count on this deduction indefinitely. At $110,000 in qualified business income, the QBI deduction saves approximately $5,100 annually. C Corp owners remain permanently excluded.

100% Bonus Depreciation Restored and Made Permanent

Bonus depreciation had been phasing down (80% in 2023, 60% in 2024, 40% in 2025 under original TCJA). OBBBA restored 100% bonus depreciation retroactively for assets placed in service from January 20, 2025 onward. This matters for S Corp owners who can claim full first-year write-offs on equipment, vehicles, and other qualifying assets at the federal level. Remember, California does not conform, so maintain those dual schedules.

$2.5 Million Section 179 Expensing Limit

OBBBA increased the Section 179 expensing limit to $2.5 million with a $4 million phase-out threshold. This applies to both C Corps and S Corps, but the pass-through nature of S Corps means you capture this deduction on your personal return alongside QBI and AB 150 benefits.

$40,000 SALT Cap

The SALT deduction cap was raised from $10,000 to $40,000 under OBBBA. While this helps individual filers, S Corp owners can bypass the cap entirely through the AB 150 PTE election, making the effective SALT deduction unlimited at the entity level.

$15 Million Estate Tax Exemption

OBBBA increased the estate tax exemption to $15 million per person ($30 million for married couples with portability under IRC Section 2010(c)(4)). This benefits business owners who plan to transfer S Corp shares to heirs, as the higher exemption shelters more of the business value from estate tax.

Three Scenarios Where Staying in a C Corp Might Make Sense

The S Corp conversion is the right move for the vast majority of California business owners, but there are three narrow exceptions where a C Corp may be the better choice.

Scenario 1: You Have a Signed VC Term Sheet

Venture capital firms require C Corp structure because S Corps cannot issue preferred stock or have institutional shareholders. If you have a signed term sheet or active fundraising with institutional investors, maintain your C Corp status. But if “raising capital” is a vague future idea with no concrete timeline, do not pay $41,000 per year in extra taxes waiting for something that may never happen.

Scenario 2: Qualified Small Business Stock (QSBS) Under IRC Section 1202

QSBS allows C Corp shareholders to exclude up to $10 million (or 10x their basis) in capital gains when they sell qualified stock held for at least five years. OBBBA expanded the QSBS tiers. However, California does not fully conform to QSBS exclusion under R&TC Section 18152.5, so the state-level benefit is limited. This matters only if you are building a company specifically for a future sale at a significant premium.

Scenario 3: Full Profit Retention Below $250,000

If your C Corp retains all profits and you take zero distributions, the 21% flat corporate rate can be lower than your individual marginal rate on pass-through income. But the moment you need that money, double taxation kicks in. And if you retain profits above $250,000 without a documented business purpose, the IRS can impose the accumulated earnings tax under IRC Section 531 at 20% on top of the regular corporate tax.

IRS Enforcement: What Palantir SNAP AI Means for Your Conversion

The IRS now uses Palantir’s SNAP AI platform to cross-reference entity classification changes against payroll filings, distribution patterns, and salary benchmarks. When you file Form 2553, the system flags your return for enhanced monitoring during the first two years of S Corp status. The AI specifically looks for unreasonable salary-to-distribution ratios, sudden drops in reported wage income post-conversion, AE&P distribution patterns that suggest dividend avoidance, and asset sales within the BIG recognition period that lack proper reporting on Schedule D and Form 4797.

This does not mean you should avoid converting. It means you need to do it correctly from day one. A properly structured conversion with documented reasonable salary, clean AE&P distribution, and accurate BIG tax baseline will pass any level of IRS scrutiny.

Frequently Asked Questions About Converting a C Corp to an S Corp

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

The IRS processes Form 2553 within 60 days and sends a confirmation letter (CP261). The California FTB processes Form 3560 within a similar timeframe. The total process from filing to confirmation takes 60 to 90 days. However, the tax benefits begin on the effective date of the election, not the confirmation date.

Do I need a new EIN after converting?

No. Your corporation keeps its existing EIN. The entity itself does not change. You are simply changing the tax classification from C Corp to S Corp. Your corporate articles of incorporation, operating agreements, and bank accounts remain the same.

Can I convert mid-year?

Form 2553 allows you to specify a prospective effective date, but it must be the first day of a tax year. If you file after the March 15 deadline, the election takes effect on the first day of the following tax year. Mid-year conversions require a split-year return under IRC Section 1362(e), where you file a short-period C Corp return and a short-period S Corp return for the same calendar year.

What happens to my C Corp net operating losses (NOLs)?

C Corp NOLs do not carry over to the S Corp. They remain suspended at the corporate level and can only be used if the entity reverts to C Corp status. This is a factor to consider if you have significant NOL carryforwards. In most cases, the annual S Corp tax savings far exceed the value of the suspended NOLs, but run the numbers to be sure.

Can I convert back to a C Corp if the S Corp does not work out?

Yes, but there is a catch. Under IRC Section 1362(g), if you revoke your S Corp election, you cannot re-elect S Corp status for five years without IRS consent. This is a serious lockout that costs the average California business owner $39,000 or more per year. Think carefully before revoking, and consider restructuring your S Corp strategy before abandoning it.

Does the conversion trigger any California taxes?

The conversion itself does not trigger a taxable event at the state level. However, if you distribute AE&P as part of the cleanup process, those distributions are taxable as dividends. California taxes dividends at ordinary income rates up to 13.3%. Plan the AE&P distribution carefully, ideally in a year when your other income is lower to minimize the state tax impact.

This information is current as of April 25, 2026. Tax laws change frequently. Verify updates with the IRS or FTB if reading this later.

“The IRS will not send you a letter telling you to convert. Every year you wait is another year you pay a tax bill that was optional.”

Book Your C Corp to S Corp Conversion Strategy Session

If you are a California C Corp owner still paying double taxation, the 8.84% franchise tax rate, and missing out on the QBI deduction, there is no reason to wait another quarter. Every month you delay costs you between $1,400 and $5,400 in avoidable taxes. Book a personalized consultation with our strategy team, and we will evaluate your BIG tax exposure, calculate your AE&P cleanup plan, set your reasonable salary, and map out your full five-layer tax savings. Click here to book your consultation now.