California S Corporation Taxation: 1.5% Tax, Form 100S, and California PTET

This catches almost every business owner who moves an S corporation into California or starts one there. You filed Form 2553 with the IRS, the federal S election went through, and you assumed California would treat the company the way the federal government does, as a pure pass-through that owes no tax of its own. California does recognize the federal election automatically, which is genuinely convenient. Unlike New York, there is no separate state-level S election to file, no California version of the federal form to chase down. The moment the IRS accepts your S status, California honors it too. But recognizing the election and taxing the entity are two different things, and California does both. It accepts that your company is an S corporation, and then it taxes that S corporation at the entity level anyway.

The tax is a franchise tax of 1.5 percent on the S corporation’s net income, reported on Form 100S, the California S Corporation Franchise or Income Tax Return. This is not a tax the shareholders pay personally. It is a tax the corporation itself owes for the privilege of doing business as a corporation in California, computed on the company’s California-source net income. So the same profit that passes through to you on your federal K-1 also gets taxed once, at the entity level, by California at 1.5 percent before it ever reaches your personal return. A federal S corporation pays zero federal income tax at the entity level. A California S corporation does not get that clean treatment from the state. The 1.5 percent is the price of the S election in California, and it surprises people because nothing about the federal process warns them it is coming.

Here is why the structure exists. When California conformed to the federal S corporation rules back in the 1980s and 1990s, it did not adopt the full federal pass-through giveaway. It kept a reduced entity-level franchise tax in place. A regular C corporation in California pays an 8.84 percent franchise tax. By electing S status, you drop the entity rate from 8.84 percent to 1.5 percent, which is a real savings at the corporate level, plus you get the federal pass-through benefit. So the S election still helps in California. It just does not make the entity-level tax disappear the way it does federally. Think of the 1.5 percent as a much smaller version of the corporate tax that survives the S election rather than a separate penalty.

Run the numbers so the cost is concrete. An S corporation with 300,000 dollars of net income sourced to California owes 4,500 dollars in franchise tax at 1.5 percent. That 4,500 dollars is owed by the corporation, on Form 100S, on top of whatever you personally owe California when the income flows through to you. The income itself starts on the federal Form 1120-S, gets divided among shareholders on each Schedule K-1, and California computes its 1.5 percent on the company’s California-apportioned share of that income. If your company also operates outside California, only the California-sourced portion feeds the 1.5 percent calculation, because California taxes the slice of income it can reach, not your nationwide total.

The good news is that the 1.5 percent franchise tax the corporation pays is a deductible business expense on the federal 1120-S, so it reduces the federal income that passes through to you. The 4,500 dollars in our example lowers the company’s federal taxable income, which softens the bite at your personal bracket. It does not erase the cost, but it takes the edge off. This is one of those details that gets missed when someone prepares their own entity return without understanding how the state and federal pieces connect, and it is exactly the kind of thing we check when we take on a California S corporation through our tax strategy consulting work. Getting the California apportionment right, so you pay 1.5 percent on the correct income figure and not a dollar more, depends on clean books, which is why we keep entity records accurate through our bookkeeping service. The point worth saying plainly is that an S election does not buy you out of California entity tax. It buys you a lower entity rate. Plan around the 1.5 percent rather than being shocked by it on the first Form 100S.

Yes, and this is the single most disliked line item in California corporate taxation. California imposes an 800 dollar annual minimum franchise tax on corporations, and an S corporation owes it whether the business made money, broke even, or lost money. The 1.5 percent tax on net income that California charges S corporations has a floor, and that floor is 800 dollars. If 1.5 percent of your California net income comes out to less than 800 dollars, you pay 800 dollars. If your company lost money for the year and has zero net income, you still pay 800 dollars. There is no version of operating a California corporation where the franchise tax drops below 800 dollars in a year you are doing business, except for one narrow exception covered below. People hate it because it feels like paying rent to the state for the privilege of existing as a corporation, which is essentially what it is.

Walk through how the floor works against the rate. Take an S corporation with 40,000 dollars of California net income. The 1.5 percent calculation gives you 600 dollars. But the minimum is 800 dollars, so the corporation pays 800 dollars, not 600 dollars. Now take an S corporation that lost 20,000 dollars for the year. There is no net income to apply the 1.5 percent to, so the rate produces zero. The corporation still pays the 800 dollar minimum. A loss year does not get you out of it. Only once your California net income climbs above roughly 53,333 dollars does the 1.5 percent calculation finally exceed the 800 dollar floor, at which point you pay the 1.5 percent figure because it is the larger number. Below that income level, the 800 dollar minimum is what you owe.

There is exactly one situation where California waives the 800 dollars, and it is worth knowing because it is the only break the state gives. A newly formed corporation does not owe the 800 dollar minimum franchise tax for its first taxable year. California carved out this first-year exemption to avoid taxing a brand-new company that may not have generated a dime of revenue yet. So if you incorporate in 2026 and that is your first California taxable year, you skip the 800 dollars for 2026. The exemption applies only to that first year, and only to the minimum tax. If your brand-new corporation actually has net income high enough that 1.5 percent exceeds 800 dollars in year one, you still owe the 1.5 percent computed tax. The waiver covers the minimum floor, not the rate. From year two forward, the 800 dollar minimum applies every single year you are in business, profit or loss.

A few traps come with this. The 800 dollars is due early, not at filing time. For an existing corporation it is owed by the 15th day of the fourth month of the taxable year, which for a calendar-year company means April 15 of the current year, paid as an estimate. People who think they can wait until they file Form 100S the following March get hit with penalties and interest for paying the minimum late. The minimum also keeps running until you formally dissolve the corporation with the California Secretary of State. A company that stops operating but never files dissolution paperwork keeps owing 800 dollars a year, because California considers it still in existence. We see this with clients who walked away from a business years ago, never dissolved it, and discover they owe back minimum taxes plus penalties for every year the shell sat dormant. If you are done with an entity, dissolve it properly so the 800 dollar meter stops.

The 800 dollars, like the 1.5 percent tax, is a deductible business expense on the federal Form 1120-S, which provides a small offset at the federal level. The company’s income still flows through to shareholders on each Schedule K-1 regardless of the minimum tax. The thing to plan for is the cash. An S corporation in California carries a guaranteed 800 dollar annual cost from its second year on, and that number matters most for the smallest companies, the side businesses and single-owner operations where 800 dollars is a meaningful fraction of the profit. For a company clearing 200,000 dollars the minimum is a rounding error. For a company clearing 15,000 dollars it can be the deciding factor in whether incorporating made sense at all. We run that math before clients incorporate through our tax strategy consulting service, and we track the minimum-tax payment dates as part of the bookkeeping work so it gets paid on time and nobody eats an avoidable penalty.

It is still available, and that is recent news worth understanding because for a while it looked like it was going away. California’s Pass-Through Entity Elective Tax, the PTET, was originally enacted as Assembly Bill 150 and applied to tax years 2021 through 2025. The whole point of it was to work around the federal cap on deducting state and local taxes. With that cap squeezing California’s high earners, who pay some of the highest state income tax in the country, the PTET let the business entity pay the owner’s California tax at the entity level, deduct it as a federal business expense, and hand the owner a credit on the personal California return. The deduction moved off the personal return, where it was capped, onto the entity return, where it was not. AB 150 was written to sunset at the end of 2025, tied to the expected expiration of the federal SALT cap.

Then the federal SALT cap got extended, which changed the calculus, and California responded. Senate Bill 132, signed on June 27, 2025, extended the California PTET for tax years 2026 through 2030. So the old 2025 sunset is gone. If you own an eligible California S corporation or partnership, the elective tax is available for 2026 and runs through 2030. The mechanics carried over largely intact. The elective rate is 9.3 percent of qualified net income, which the entity pays on behalf of consenting owners. Each owner then claims a credit on their California personal return for their share of the PTET the entity paid, so they are not taxed twice on the same income. The election is annual, made on the entity’s California return, and California uses Form 3804 to calculate the elective tax and Form 3893 as the payment voucher.

The federal SALT facts are what make this matter, and the 2026 numbers are not what most people still assume. The federal cap on deducting state and local taxes is 40,400 dollars for 2026, not the old 10,000 dollar figure people quote from memory. It is 20,200 dollars for married filing separately. But that higher cap phases down for high earners. Above 505,000 dollars of modified adjusted gross income, the cap shrinks by 30 cents for every dollar of income over that threshold, grinding back down toward a 10,000 dollar floor at around 606,333 dollars of income. Most of the California high earners this firm serves land right near that floor, which is the whole reason the PTET still earns its keep. If your personal SALT deduction is effectively capped at 10,000 dollars because your income pushed you through the phasedown, moving your California tax onto the entity return through the PTET recovers a federal deduction you would otherwise lose. The higher cap runs through 2029 and then reverts to a flat 10,000 dollars on January 1, 2030, which is exactly when California’s extended PTET also winds down. The two were designed to expire together.

The deadlines are where California’s PTET bites the unwary, because there is a prepayment due in the middle of the tax year. To make a valid election for a given year, the entity has to make a prepayment by June 15 of that tax year. The prepayment equals the greater of 1,000 dollars or 50 percent of the prior year’s PTE tax. Miss the June 15 prepayment and the election is gone for the entire year, with no late relief. This trips up companies that decide late in the year they want the PTET, only to learn the window closed in June. The remaining balance of the elective tax is then due by the original due date of the entity return the following March. So the California PTET runs on a split schedule: a mandatory June 15 prepayment to keep the election alive, and the balance with the return.

Here is the concrete payoff. An S corporation with 300,000 dollars of qualified net income elects the PTET and pays 9.3 percent, which is 27,900 dollars, to California at the entity level. The entity deducts that 27,900 dollars on the federal Form 1120-S as a business expense, lowering the income that passes through to owners on each Schedule K-1. At a 37 percent federal bracket, deducting that 27,900 dollars saves roughly 10,300 dollars in federal tax that the SALT cap would otherwise have swallowed. The owners then take a credit on their California personal returns for the PTET the entity paid, so California is made whole and the owners are not double-taxed. The net is a federal savings of around ten thousand dollars on this example, achieved purely by routing the California tax through the entity. That is real money, and for a high-earning California owner it is often the largest single planning move on the table. We model the election, the June 15 prepayment, and the personal-return credit together through our tax strategy consulting service. There is a fuller walk-through in our guide to the California PTE elective tax if you want the deadline detail in one place.

The entity-level taxes are only half the story. Once the 1.5 percent franchise tax is paid on Form 100S, the S corporation’s income still passes through to you personally, and you owe California personal income tax on it on top of the entity tax. This is the double layer that makes California S corporations expensive for high earners. The company pays 1.5 percent at the entity level, and then the same income flows through to your personal return and gets taxed at California’s personal rates, which are the highest in the country. So the profit gets taxed twice in California, once lightly at the corporate level and once at your full personal bracket. Understanding both layers is the only way to know what your S corporation actually costs you in California.

The pass-through mechanics start federally. The S corporation reports its income on the federal Form 1120-S and divides it among shareholders, issuing each owner a Schedule K-1 showing their share. That K-1 income lands on your federal Form 1040 through Schedule E, which is where income from S corporations and partnerships is reported on the individual return. From there it flows into your federal adjusted gross income. California starts its personal return with that federal income and then applies its own modifications, because California does not conform to every federal rule. The chain runs from the entity return, to the federal K-1, to Schedule E on the 1040, to federal AGI, and then onto the California personal return where the state computes its tax.

Now the rates, which are the reason this matters so much in California. California’s personal income tax tops out at 13.3 percent. That figure is a 12.3 percent top marginal rate plus an additional 1 percent surcharge, the mental health services tax, on taxable income over 1,000,000 dollars. So a California resident with a high-income S corporation can see the pass-through income taxed at 13.3 percent personally, after the company already paid 1.5 percent at the entity level. Stack those and California is taking a serious cut. This is precisely why the PTET election covered elsewhere on this page matters so much for California owners. By routing the California personal tax through the entity as a deductible PTET payment, a high earner recovers a federal deduction that the SALT cap would otherwise eliminate. Without that planning, the combination of the 1.5 percent franchise tax, the up-to-13.3 percent personal rate, and a capped federal SALT deduction is about as heavy as state taxation gets in the United States.

The nonresident question changes things, and it is one of the most misunderstood areas for owners who do not live in California. If you own a California S corporation but live in another state, California still taxes your share of the California-source income. California reaches income earned within its borders regardless of where the owner lives. So a nonresident shareholder of a California S corporation files a California nonresident return, Form 540NR, and pays California tax on the California-source portion of their K-1 income. You do not escape California tax simply by living in Texas or Nevada. If the business operates in California and generates California-source income, your slice of that income is taxable to California even as a nonresident. What a nonresident does not pay California tax on is income from outside California, so if the company operates in multiple states, only the California-apportioned share hits your California nonresident return.

The wrinkle that costs nonresidents money is the credit for taxes paid to other states. As a nonresident paying California tax on California-source income, you then report that same income on your home-state resident return, because your home state taxes your worldwide income. To avoid being taxed twice on the same dollars, your home state generally gives you a credit for the tax you paid to California. Getting that credit right requires coordinating the California nonresident return with the home-state return, and it is easy to leave money on the table if the two are prepared in isolation. A New York resident who owns a piece of a California S corporation, for instance, pays California on the California-source share and then claims a credit on the New York return for that California tax. We handle exactly this kind of multi-state coordination as part of our individual tax return preparation service, and we model the resident-versus-nonresident outcome in advance through our tax strategy consulting work so an owner deciding where to live, or where to source the business, understands the real California cost before the return is filed rather than after.

An S corporation in California carries a stack of fixed costs and hard deadlines, and the honest answer is that for some businesses it is clearly worth it and for others it is not. The S election saves money federally by splitting the owner’s pay into reasonable salary and distributions, with only the salary hit by payroll tax. But California layers its own costs on top, and those costs do not scale down for a small business. Below a certain profit level, the California-specific costs eat the federal savings and a plain LLC or sole proprietorship comes out ahead. Knowing where that line sits for your numbers is the difference between an S corporation that saves you thousands and one that quietly costs you money every year.

Start with the deadlines, because missing them adds penalties to costs you already owe. Form 100S, the California S corporation return, is due March 15 for a calendar-year company, the same day as the federal Form 1120-S. Both returns can be extended six months to September 15, the federal one through Form 7004 and the California one automatically. But an extension to file is not an extension to pay. The 800 dollar minimum franchise tax estimate for the current year is due April 15. If you want the PTET, the prepayment is due June 15 of the tax year. Personal estimated payments on the owner’s side run April, June, September, and January. That is a calendar with payments scattered across the whole year, and California charges interest on anything paid late regardless of any filing extension.

Now add up the fixed California costs so the real number is visible. Every California S corporation pays the 800 dollar minimum franchise tax annually from its second year forward, profit or loss. It pays the 1.5 percent franchise tax on net income once income climbs above roughly 53,333 dollars, where 1.5 percent exceeds the 800 dollar floor. On top of those state-mandated costs sit the practical expenses of running a corporation properly: payroll setup and quarterly payroll filings to pay the owner a reasonable salary, a separate corporate tax return, and the bookkeeping needed to keep the entity’s records clean enough to file. None of that exists for a sole proprietor who just files a Schedule E or Schedule C on their personal Form 1040. The corporation is a real administrative load with real annual cost.

Weigh that against the benefit, which is the federal payroll-tax savings. The S election lets the owner take part of the profit as distributions that escape Social Security and Medicare tax, the tax a sole proprietor pays in full through the Schedule SE self-employment computation. The salary portion still gets payroll tax, but the distribution portion does not. So the savings depends on how much profit you can reasonably move from salary to distribution. The reasonable salary has to be defensible, what you would pay an outside person to do your job, so you cannot take a token salary and call the rest distributions. The IRS reclassifies unreasonably low salaries and assesses back payroll tax. There is also the qualified business income deduction the owner may claim through Form 8995, which interacts with the salary level, so the salary decision ripples into more than just payroll tax.

Put the two sides together and the break-even becomes clear. For an S corporation to be worth it in California, the federal payroll-tax savings on the distribution portion has to exceed the stack of California costs: the 800 dollar minimum, the 1.5 percent franchise tax, payroll administration, and the extra return. As a rough rule, that crossover tends to happen once net profit clears the rough range of 60,000 to 80,000 dollars a year, where the payroll-tax savings on distributions finally outruns the California overhead, though the exact line depends on your salary level, your state, and how much of the profit can reasonably be taken as distribution. Below that range, the California costs usually win and a simpler structure makes more sense. Anyone who tells you an S corporation is always the right call in California has not run this math. We run it for every client considering the election through our tax strategy consulting service, and we keep the entity books clean enough to file Form 100S correctly and to support a defensible salary through our bookkeeping work. The S corporation is a tool, not a default. It pays off above the break-even and costs you below it, and the only way to know which side of that line you are on is to put your actual numbers through the calculation before you incorporate.