California Exit Tax + AB-150 PTET: $10M Founder Sale Trap

California does not have a formal exit tax. The proposals are real — AB 2088 in 2020 would have imposed a 0.4% annual wealth tax that continued for ten years after departure; AB 310 in 2021 was a similar proposal — but none have been enacted. What California has instead is residency-based taxation that operates as an exit tax in practice when founders try to sell after relocating. The Franchise Tax Board taxes residents on worldwide income at rates that top out at 13.3% (14.4% with the 1% mental-health surcharge on income above $1 million), and the residency determination under Cal. Rev. & Tax Code section 17014 is fact-intensive rather than day-count-based. A founder selling $10 million of QSBS-eligible stock while a California resident pays $1.33 million in state tax even though the federal exclusion under section 1202 wipes the federal liability to zero. California does not conform to section 1202 — the federally-excluded gain is fully CA-taxable.

AB-150, California's Pass-Through Entity Tax election enacted in 2021, layers a second problem on top of the residency exposure. The PTET was designed as a SALT-cap workaround: the entity pays 9.3% CA tax on qualified net income at the entity level, and the federal deduction for that tax bypasses the $10,000 personal SALT cap. The mechanics work cleanly in normal operating years. In a sale year with a $10 million one-time gain flowing through the entity, the PTET creates a prepayment problem and an interaction with partial-year residency that founders routinely fail to model. This article walks through both the residency-exit math and the AB-150 interaction, and provides the 6-12 month clean-break checklist for founders selling at $10M+.

The California residency machine: closest-connections, not day-count

California's residency test is not a bright-line rule. Section 17014 defines a resident as anyone present in California for other than a temporary or transitory purpose, plus anyone domiciled in California who is absent for a temporary or transitory purpose. There is a 9-month presumption — anyone in California for more than 9 months in a tax year is presumed a resident — but this is a floor, not a safe harbor. A founder who spends 8 months in California is not safe; the FTB still applies the closest-connections test.

The leading authority on the closest-connections analysis is Bragg v. Franchise Tax Board (2003), which established a multi-factor test now codified in FTB Publication 1031. The factors include: location of primary home, location of spouse and children, location of bank accounts and investment accounts, location of doctor, dentist, attorney, and accountant, voter registration, driver's license, vehicle registration, where you receive mail, club memberships, professional licenses, and where you spend your time. No single factor controls; the FTB looks at the totality.

The factors that move the needle most heavily in audit practice: where the family lives, where the primary home is, and where the children attend school. A founder who buys a Texas apartment, gets a Texas driver's license, and registers to vote in Texas — but keeps the family home in Palo Alto, leaves the kids in CA schools, and maintains the same CA accountant and attorney — loses an FTB challenge. Establishing California non-residency requires substantive life relocation, not a paperwork move.

The QSBS Section 1202 non-conformity hit

IRC section 1202 allows founders of qualifying C-corporations to exclude the greater of $10 million or 10 times adjusted basis from federal capital gains tax on the sale of qualified small business stock held for at least 5 years. For stock acquired after September 27, 2010, the exclusion is 100% — meaning zero federal tax on the excluded portion, no NIIT, and no AMT preference. The federal savings on a $10 million QSBS sale at the 23.8% combined rate (20% LTCG plus 3.8% NIIT) is $2.38 million.

California does not conform. The state has not adopted section 1202, and the FTB taxes the gain on QSBS sales at the full California rate. For a California-resident founder selling $10 million of QSBS:

• Federal tax: $0 (full section 1202 exclusion)
• California tax: $10,000,000 × 13.3% = $1,330,000
• California 1% mental-health surcharge (if applicable on income over $1M): up to $100,000 additional
• Total state tax: approximately $1,430,000

On a $40 million exit with $10 million qualifying for QSBS, the math gets worse. The federal exclusion saves $2.38 million; the California tax on the full $40 million is approximately $5.32 million. California collects more than twice what the federal government does, and the QSBS structure provides zero California benefit. This is the configuration that drives the pre-sale residency move for high-value California founder exits.

AB-150 PTET: how the SALT-cap workaround becomes a sale-year trap

AB-150, enacted in July 2021 and refined by SB 113 in February 2022, created California's Pass-Through Entity Tax election. The basic mechanics: an eligible pass-through entity (S-corp, partnership, or LLC taxed as partnership) can elect to pay 9.3% California tax on qualified net income at the entity level. The federal benefit comes from IRS Notice 2020-75, which blesses entity-level state-tax deductions as not subject to the $10,000 personal SALT cap that TCJA imposed on owners.

The federal deduction is real and meaningful for normal operating income. An entity with $2 million of qualified net income that elects PTET pays $186,000 in CA tax at the entity level, deducts that $186,000 on the federal return (reducing federal taxable income for the owners), and each owner receives a non-refundable credit on their California personal return equal to their share of the PTET paid. At a 37% federal rate, the deduction saves owners approximately $68,820 in federal tax — a real benefit that recurs annually.

The trap appears in a sale year. Consider an S-corp with two equal owners that historically had $2 million in annual net income and elected PTET each year. In Year 5, the owners sell the business in an asset sale for $20 million with $1 million in basis, generating $19 million of gain that flows through to the owners. If the PTET election is in place for Year 5:

• Total entity-level income for PTET purposes: $2 million operating plus $19 million gain = $21 million
• PTET due (9.3% of qualified net income): approximately $1,953,000
• Each owner's share of PTET credit: $976,500
• Each owner's CA personal tax on their share of total income ($10.5 million at 13.3% top rate, with progressive brackets): approximately $1,200,000
• Each owner uses $976,500 of PTET credit, owes additional $223,500 in CA tax
• Net CA tax position: $2,400,000 between both owners — same as if no PTET election had been made
• Federal deduction benefit on $1,953,000 entity-level CA tax at 37%: $722,610 federal savings

This looks like a win — $722,610 in federal tax savings from the PTET election. But three problems emerge when one or both owners are planning to relocate before the sale or have already moved partway through the year.

Problem 1: PTET credit is non-refundable

The PTET credit can only offset California personal income tax. If an owner has insufficient CA personal tax liability — because they relocated and most of their income is now non-CA source — the credit is wasted. For an owner who moves to Texas mid-year and has $500,000 of CA-source income but $976,500 of PTET credit, $476,500 of credit is stranded. There is a 5-year carryforward under R&TC section 17052.10(b)(3), but the credit cannot offset non-CA income or be refunded.

Problem 2: Partial-year residency interacts badly

Form 540NR (the part-year resident return) applies a proration formula that calculates CA tax on the full income and then prorates based on the percentage of CA-source income. If a founder moves to Nevada in February of the sale year and the sale closes in June, the FTB looks at the entire year's income and the CA-source portion. PTET credits earned on entity income that may now be partly non-CA-source create a calculation that the FTB scrutinizes carefully — and in audit, the burden is on the taxpayer to demonstrate the sourcing.

Problem 3: Election lock-in

The PTET election is annual but must be made by the due date of the entity's first estimated payment (June 15 of the tax year). Once made, it cannot be revoked for that tax year. A founder who elects PTET in March based on normal-year planning, then identifies a buyer in May and accepts a closing date in October, is locked into the PTET election for the sale year — even if the math now disfavors the election.

Worked example: $10M QSBS sale, three scenarios

Sarah and Michael co-founded a SaaS company as a Delaware C-corporation in 2018 with $100,000 of total basis ($50,000 each). The company is headquartered in San Francisco. Both founders are California residents. In 2026, they accept a buyer offer of $20 million for a stock sale — $10 million each. Both founders' shares qualify for section 1202 QSBS treatment (held 8 years, original issuance, $50,000 basis each, company never crossed $50 million in gross assets during the qualifying period). Each founder will exclude $10 million federally.

Scenario A: stay in California, no PTET election

Sarah and Michael remain California residents through the sale. The C-corp does not elect PTET (PTET is largely irrelevant to C-corp stock sales because the gain is recognized at the shareholder level, not flowing through a pass-through entity).

• Federal tax: $0 (full QSBS exclusion on first $10M each)
• California tax per founder: $10,000,000 × 13.3% = $1,330,000
• California mental-health surcharge (1% on income over $1M): approximately $90,000 each
• Total California tax: approximately $2,840,000 between both founders
• After-tax proceeds per founder: $10,000,000 minus $1,420,000 = approximately $8,580,000

Scenario B: rushed move 60 days before sale, FTB audit loss

Sarah and Michael learn of the buyer interest in March, sign an LOI in May, and attempt to establish Texas residency in June. They acquire Texas apartments, file change-of-address forms, and update voter registration. The sale closes August 1. Both file Form 540NR claiming non-resident status from June 15 forward. The FTB audits in 2028.

In the audit, the FTB notes that Sarah's spouse remained in California, her children stayed in CA schools, she maintained her CA medical providers, her cell-phone records show 90% of June and July nights spent in California, and her Texas apartment was utility-light. The FTB rules she remained a California resident through the closing date. Same outcome for Michael.

• Audit-adjusted CA tax per founder: same as Scenario A — approximately $1,420,000
• FTB penalties (accuracy-related, 20% under R&TC section 19164): $284,000 each
• Interest (compounded, approximately 7% per year over 2 years): approximately $200,000 each
• Total cost per founder: approximately $1,904,000
• Total cost between both founders: approximately $3,808,000
• After-tax proceeds per founder: $8,096,000

Scenario C: clean 12-month move to Texas, no PTET issue

Sarah and Michael begin the relocation in August of the year before the planned sale. They sell their California homes, purchase Texas homes, move spouses and children, change schools, update driver's licenses and voter registrations within 30 days, transfer all banking and medical providers, and limit CA presence to fewer than 30 days during the 12 months before closing. The sale closes the following August. They file Form 540NR for the partial-year transition (the move year) and full Texas-only returns for the sale year.

• Federal tax: $0 (full QSBS exclusion)
• California tax per founder on the sale: $0 (Texas residents at closing; California has no source-income claim on stock-sale gain by non-residents)
• Texas state tax: $0 (no personal income tax)
• After-tax proceeds per founder: $10,000,000
• Net benefit per founder vs. Scenario A: approximately $1,420,000
• Net benefit between both founders: approximately $2,840,000

The decision lever that mattered in Scenario C: starting the move 12 months before the sale. The rushed 60-day move in Scenario B failed the closest-connections test because the family, the schools, the doctors, and the time spent in California all anchored residency. The 12-month move severed those anchors before the FTB had any audit trigger.

The AB-150 PTET decision for sale-year pass-through entities

If the selling entity is an S-corp, partnership, or LLC taxed as partnership — as opposed to a C-corporation — the PTET election decision becomes part of the pre-sale planning. The framework:

• Founders staying in California: PTET election generally beneficial. The federal deduction (saving ~37% of the PTET amount) offsets the lack of incremental CA savings. On a sale generating $10M of flow-through gain to two CA-resident founders, the PTET saves approximately $344,100 in federal tax (37% of $930,000 PTET on the $10M gain) with no offsetting CA cost.
• Founders moving out of California before the sale year: PTET election should be avoided. The credit becomes stranded because non-CA-source income (sale of stock by a non-resident) does not absorb the credit. The federal deduction benefit is preserved but the CA-level cost of the entity-level payment may not be fully recovered.
• Founders making a partial-year move during the sale year: the most complex case. Model both scenarios: PTET vs no PTET. The PTET credit will be limited by the CA-source portion of personal income, and the carryforward may have limited use if the founder will not earn future CA-source income. Generally, in close cases, avoid the election in the move year to preserve flexibility.
• Founders with multiple owners on different residency tracks: the election binds all owners. If one owner is moving and another is staying, the election must be evaluated against the staying owner's benefit versus the moving owner's stranding risk. In practice, this often requires the moving owner to be cashed out before year-end or for the election to be skipped that year.

The 6-12 month clean-break checklist

For a founder selling at $10M+ who has decided to relocate from California, the residency-establishment work should begin at least 6 months before the sale closing — 12 months is better. The checklist:

• Sell or lease out the California primary residence. Keeping a California home while claiming non-residency is the single largest FTB audit trigger. If retained, lease at fair-market rent to an unrelated third party with a written lease and arms-length terms; do not occupy the property during the lease term except for documented brief visits.
• Acquire a new-state primary residence. Purchase or lease for a term of at least 12 months. Set up utilities, internet, and routine services in your name with the new address.
• Move the family. If your spouse remains in California and children remain in CA schools, the closest-connections test will likely treat you as still a California resident regardless of your individual paperwork. This factor is often determinative.
• Update driver's license and voter registration within 30 days. California has reciprocity agreements that make a new-state driver's license straightforward. Voter registration in the new state is similarly fast.
• Transfer banking and brokerage accounts. Update primary address on all financial accounts. Establish a local banking relationship in the new state.
• Update medical, dental, legal, and accounting providers. Establish new local providers and document the transition. CA professional services maintained during the post-move period are a common FTB audit finding.
• Update estate documents. Re-execute will, trust, and powers of attorney under new-state law. This signals domiciliary intent.
• Limit California days. Aim for fewer than 45 days in California per tax year during the transition. Document trips with hotel receipts and business purposes.
• Document everything. Save cell-phone bills (showing tower geographic data), credit-card statements (showing transaction locations), social-media posts, and travel itineraries. In an FTB audit, the burden of proof is on the taxpayer.
• File Form 540NR for the transition year and zero CA filing thereafter. File complete and accurate partial-year returns; do not under-report CA-source income from the transition year. Aggressive under-reporting triggers more audits than properly disclosed partial-year filings.

FTB audit triggers and burden of proof

The FTB's residency audit rate on high-asset partial-year movers is materially higher than baseline. Common audit triggers: filing Form 540NR in the year of a high-value transaction; selling a business with CA nexus while claiming non-residency; maintaining a CA home; CA driver's license or voter registration remaining active after the claimed move; CA professional licenses remaining in resident status. The audit typically reviews 18 to 36 months of life-in-CA evidence including cell-phone records, credit-card transactions, social-media check-ins, IP addresses on email accounts, and statements from former California neighbors or employees.

Burden of proof in California residency challenges falls on the taxpayer under R&TC section 17014. The FTB does not have to prove you were a resident; you have to prove you were not. This evidentiary structure is the reason a documented 6-12 month move with the elements above wins audits and a rushed 60-day move loses them. Engage a California-tax-residency-experienced CPA or attorney before the sale year — the cost of building the residency-defense file in advance is small relative to the tax exposure on a misjudged move.

Where the opposite is right: when to stay in California

The relocation analysis assumes the founder is willing to actually move. For many founders, family location, schools, climate, healthcare networks, and community ties make California the right place to live even at a $1M+ state-tax cost. The point of this article is not that every founder should relocate — it is that founders who do plan to relocate should execute the move properly, and founders who plan to stay should know what they are paying for.

Cases where staying in California makes more financial sense than expected: founders whose business will continue operating in California with material employee or customer presence — the FTB source-income rules under section 17951 can pull post-move income back into CA tax even after a successful residency change. Founders with significant California real estate that they intend to retain — CA-situs property income remains CA-source regardless of owner residency. Founders whose family circumstances make a clean break impossible. In these cases, focus on federal optimization (QSBS structuring, installment sales, donor-advised funds for the charitable portion) rather than state-residency planning.

Key takeaways

• California has no formal exit tax, but FTB residency-based taxation at up to 13.3% (plus 1% mental-health surcharge over $1M) functions as an exit tax in practice for selling founders. California does not conform to QSBS Section 1202 — a $10M federally-excluded sale carries approximately $1.33M of California tax for resident sellers.
• The closest-connections test from Bragg v. FTB controls residency determinations. There is no bright-line day count. The factors that move the audit needle most: location of family, primary home, children's schools, and time spent. Rushed 60-day moves before a sale routinely lose FTB audits.
• AB-150 PTET is a real federal-deduction win for California pass-through entities in normal operating years, but creates traps in sale years: non-refundable credits that can be stranded for partial-year movers, annual election lock-in that cannot be revoked, and complex interaction with Form 540NR sourcing rules.
• The 6-12 month clean-break checklist works: sell or lease the CA home at fair-market rent to an unrelated party, move the family, update driver's license and voter registration within 30 days, transfer all financial and medical providers, limit CA days to under 45 per year, and document with cell-phone records and credit-card transaction history.
• On a $10M QSBS sale, the difference between a successful 12-month relocation and staying in California is approximately $1.42M per founder. The cost of building the residency-defense documentation in advance is small relative to that exposure. Engage a CA-residency-experienced CPA before the sale year, not after.
• The relocation analysis is not universal advice. Founders with family ties, ongoing CA business operations, or significant CA-situs property may rationally choose to stay and absorb the state tax. For those founders, federal optimization through QSBS structuring, installment sales, and charitable deployment carries the planning weight.