NY State Tax + Business Sale: Source-Income Rules Decoded

New York taxes residents on worldwide income at rates that reach 10.9 percent at the state level (top bracket on taxable income above $25 million) under NY Tax Law section 601. New York City residents add 3.876 percent in NYC personal income tax under NYC Administrative Code section 11-1701, producing a combined top marginal rate of approximately 14.776 percent — higher than California's 13.3 percent state-only rate. For founders selling at $5 million or more, this combined federal-state-city stack is among the highest tax burdens in the country.

The planning question for selling founders is the same as in California: stay and absorb the tax, structure around it, or relocate before closing. The mechanics differ. New York's residency framework under section 605 distinguishes between domicile (the primary determinant) and statutory residency (a 183-day-plus-permanent-place-of-abode rule). The state's source-income rules for non-residents under section 632 treat stock and partnership interests as non-NY-source for intangible-property sales — a meaningful planning lever that California does not provide. This article walks through the resident-versus-non-resident determination, the source-income rules that govern non-resident treatment, the QSBS conformity (which is favorable), and the planning math for $1M+ founder sales.

New York rate structure: state plus NYC for Manhattan residents

The New York state rate brackets for 2026 (subject to annual adjustment under section 601) include:

• 4 percent up to $8,500 single / $17,150 joint
• 4.5 percent to 6.85 percent through middle income
• 9.65 percent on taxable income above $1,077,550 single / $2,155,350 joint
• 10.30 percent on taxable income above $5 million single / $5 million joint
• 10.90 percent on taxable income above $25 million single / $25 million joint

For founders recognizing a one-time multi-million-dollar gain on a sale, the marginal rate hits the top 9.65 percent, 10.30 percent, or 10.90 percent bracket depending on size. The blended effective rate on a $5 million gain for a New York-resident single filer is approximately 9.4 percent at the state level.

New York City residents pay additional NYC personal income tax on top of the state rate. The NYC PIT brackets for 2026:

• 3.078 percent up to $12,000 single
• 3.762 percent to $25,000 single
• 3.819 percent to $50,000 single
• 3.876 percent above $50,000 single

The NYC PIT applies to NYC residents on worldwide income — there is no separate sourcing rule for the city level. For a Manhattan founder, the combined effective state-plus-NYC rate on a $5 million gain is approximately 13.3 percent. Stacked with federal LTCG of 20 percent plus NIIT of 3.8 percent, the total tax burden reaches approximately 37 percent.

Domicile versus statutory residency under section 605

New York's residency framework has two paths, either of which makes a taxpayer a New York resident:

Path 1: Domicile

Domicile is the place an individual considers home — where they have their permanent and principal residence and to which they intend to return. New York applies a multi-factor test similar to the California closest-connections analysis. Factors include:

• Location of primary residence (NY versus elsewhere)
• Location of family (spouse and minor children)
• Time spent in each location
• Location of items of personal and emotional value (heirlooms, family photographs, pets)
• Business connections (where the taxpayer's active business interests are based)
• Where the taxpayer holds professional licenses, club memberships, and community ties
• Voter registration and political activity
• Driver's license and vehicle registration

A taxpayer who is domiciled in New York is a New York resident for income-tax purposes regardless of physical presence. Domicile changes once established carry forward until the taxpayer affirmatively abandons New York domicile and establishes a new domicile elsewhere. This is the framework that controls most pre-sale relocation cases.

Path 2: Statutory residency

Under section 605(b)(1)(B), a taxpayer who is not domiciled in New York is still treated as a statutory resident if both: (1) the taxpayer maintains a permanent place of abode in New York for substantially all of the tax year, AND (2) the taxpayer spends more than 183 days in New York during the tax year. The permanent-place-of-abode test does not require ownership — a leased apartment, a parental home where the taxpayer maintains a room, or even sustained access to a corporate apartment can satisfy the test if it provides residential accommodations on a year-round basis.

The statutory-residency rule catches taxpayers who have changed domicile to another state but still maintain a New York apartment for business or family reasons and spend more than 183 days in New York. The 183-day count is strict — partial days in New York generally count as full days under Department of Taxation and Finance regulations. For founders who change domicile to Florida but maintain a Manhattan pied-a-terre and spend significant time in New York for board meetings, fundraising, or family commitments, the statutory residency rule can pull them back into New York resident status.

The 548-day rule: limited utility for US-domestic moves

Section 605(b)(1)(A)(ii) provides the 548-day rule: a New York domiciliary is treated as a non-resident for income-tax purposes if the taxpayer is outside New York for at least 450 days during a 548-day period, the taxpayer's spouse and minor children are also outside New York for the same period (with limited exceptions for children attending New York schools), and the taxpayer does not spend more than 90 days in New York during the 548-day period.

The rule was originally designed for taxpayers working abroad — diplomats, foreign correspondents, expatriate executives — who would lose New York domicile under a typical multi-factor analysis but should not be treated as residents during the foreign assignment. Historical Department of Taxation and Finance interpretations excluded US-domestic relocations from the rule, on the theory that a move from Manhattan to Miami required actually changing domicile rather than satisfying a timing test.

More recent technical guidance has clarified the rule but the practical effect for founders selling at $5M+ remains: changing domicile through a documented permanent move is required to escape New York taxation on the sale gain, not merely satisfying the 548-day timing test. The 548-day rule is not a shortcut around the multi-factor domicile analysis for ordinary US-domestic relocations.

Non-resident source-income rules under section 632

For a taxpayer who is NOT a New York resident (neither domiciliary nor statutory resident), New York taxes only New York-source income under section 632. The sourcing rules for business-sale transactions:

• Tangible personal property: Gain on the sale of tangible personal property located in New York is New York-source income regardless of seller domicile. A non-resident selling New York-located equipment in an asset sale recognizes NY-source gain.
• Real property: Gain on the sale of New York real property is New York-source income for non-residents under section 632(b)(2). This is the broadest non-resident hook — even a 30-year-prior New York resident who has been domiciled in Texas for decades pays NY tax on a sale of New York real estate.
• Intangible personal property: Gain on the sale of intangible personal property (stock, partnership interests, LLC membership interests, goodwill, intellectual property) is generally NOT New York-source income for a non-resident under the general rule.
• Pass-through entity income with NY apportionment: Gain attributable to a pass-through entity's New York business apportionment is allocable to New York for non-resident owners. This catches partnership interest sales where the underlying partnership conducts business in New York — the non-resident seller may still owe NY tax on the apportioned NY share.
• Compensation for personal services: Gain on the sale of an interest that represents compensation for personal services performed in New York (rare in clean stock sales but relevant for some founder-employee equity) may be sourced to New York under a personal-services apportionment.

The critical lever for founders: stock sales of New York-operating C-corporations by genuine non-residents are typically NOT New York source income. A former New York founder who genuinely changes domicile to Florida and sells stock in a Manhattan-based C-corporation 12 months later pays $0 of New York tax on the gain, even though the corporation operates in New York. This is meaningfully different from California, which uses a similar general rule but has more aggressive audit posture and source-income claims on certain transactions.

QSBS Section 1202: New York conforms

New York Tax Law section 612 conforms to the federal definition of adjusted gross income with statutory modifications. The federal section 1202 QSBS exclusion flows through to the New York tax base — meaning a New York-resident founder selling qualified small business stock who meets the federal section 1202 holding period and other requirements excludes the same gain from New York income.

For a New York resident selling $10 million of QSBS-eligible stock:

• Federal tax: $0 (full section 1202 exclusion at federal level)
• New York state tax: $0 (state conforms to federal exclusion)
• NYC tax (if Manhattan resident): $0 (NYC conforms to NY state computation)
• Total tax: $0

This is a major planning lever for New York founders. The combination of section 1202 conformity and the section 632 non-resident treatment of intangibles means that QSBS-eligible New York founders have two distinct planning paths:

• Stay in New York and rely on QSBS. For founders whose entire $10M of gain qualifies for section 1202 treatment, staying in New York costs $0 of state tax. This is identical to relocating to Texas or Florida.
• Relocate for the non-QSBS portion. For founders whose gain exceeds the $10M QSBS cap (or 10x basis), the excess gain is fully taxable in New York. Relocation eliminates New York tax on the excess.

Worked example: $15M founder exit, four scenarios

David is a Manhattan-based co-founder of a Delaware C-corporation operating a fintech company. He owns 30 percent of the equity and the company is sold for $50 million in a stock sale. David's gain: $15 million. His shares qualify for section 1202 QSBS treatment ($10 million federally excluded, $5 million taxable federally at the 23.8 percent combined LTCG-plus-NIIT rate). The federal tax on the $5M non-QSBS portion is $1,190,000.

Scenario A: David stays in NY/NYC throughout

• Federal tax: $1,190,000 (QSBS excludes first $10M)
• NY state tax: $0 on QSBS portion ($10M); approximately $483,000 on the $5M non-QSBS portion (NY blended at ~9.6 percent)
• NYC tax: $0 on QSBS portion; approximately $194,000 on the $5M non-QSBS portion (3.876 percent)
• Total state-plus-NYC tax: approximately $677,000
• Total tax: approximately $1,867,000
• After-tax proceeds: approximately $13,133,000

Scenario B: David relocates to Florida 12 months before sale

David sells his Manhattan apartment, purchases a Miami Beach home, moves his wife and one school-age son in time for the August school year, applies for Florida driver's license within 30 days, registers to vote in Florida, files for Florida homestead exemption, transfers banking, professional services, and medical providers. The sale closes 12 months after the move. He files a partial-year NY return for the transition year and a full Florida-resident year for the sale year.

• Federal tax: $1,190,000 (QSBS preserved regardless of state)
• NY state tax: $0 (Florida resident on closing date; stock sale of Delaware C-corporation by a non-resident is not NY-source under section 632)
• NYC tax: $0 (non-resident)
• Florida tax: $0 (no personal income tax)
• Total tax: $1,190,000
• After-tax proceeds: $13,810,000
• Savings versus Scenario A: $677,000

Scenario C: David relocates but maintains a Manhattan pied-a-terre, fails statutory residency

David purchases the Florida home and files Florida documentation, but keeps his Manhattan apartment for occasional use and continues to spend 4 months per year in New York for board meetings, family commitments, and social events. The Department of Taxation and Finance audits and finds that David maintained a permanent place of abode in New York and spent more than 183 days in New York during the tax year (counting partial-day NY presence). He is classified as a NY statutory resident.

• Federal tax: $1,190,000
• NY state tax: approximately $483,000 (full NY state tax applies as a resident)
• NYC tax: depends on whether the Manhattan apartment establishes NYC residency separately — if yes, additional $194,000
• Penalties and interest from the audit: approximately $135,000
• Total tax: approximately $2,002,000
• After-tax proceeds: approximately $12,998,000
• Worse than Scenario A by approximately $135,000 due to penalties

Scenario D: David uses an installment sale and relocates between payments

David structures the sale as a 5-year installment: $3M of gain recognized each year from 2026 through 2030. He sells while a NY resident in 2026 (recognizing $3M as NY income that year) and relocates to Florida in early 2027 (so 2027 through 2030 installments are received as a Florida resident). He files Form IT-203 (NY non-resident return) for installment payments received after relocation.

• Federal tax: $1,190,000 (recognized across years)
• NY tax on 2026 portion ($3M): approximately $289,000 plus NYC $116,000 equals $405,000
• NY tax on 2027-2030 portions ($12M as non-resident, intangible-property gain): $0
• Florida tax: $0
• Total tax: approximately $1,595,000
• After-tax proceeds: approximately $13,405,000
• Savings versus Scenario A: approximately $272,000
• Savings versus Scenario B: negative — Scenario B (pre-sale relocation) is better by approximately $405,000

The decision tree for New York founders

The planning decision for a New York-based founder depends on the gain mix between QSBS-eligible and non-QSBS portions:

• Gain entirely within QSBS cap (typically <$10M). Staying in New York costs $0 of state tax. There is no financial reason to relocate purely for tax purposes.
• Gain modestly above QSBS cap ($10M-$20M total, $0-$10M non-QSBS). The non-QSBS portion incurs approximately 13.5 percent combined NY state and NYC tax. On a $10M non-QSBS portion, this is approximately $1.35M of tax. Relocation can save this amount but requires a documented domicile change. Decision depends on willingness to actually move.
• Gain substantially above QSBS cap ($20M+ total, $10M+ non-QSBS). The non-QSBS portion incurs $1.35M+ of NY tax that grows linearly with the gain. Relocation almost always justified financially, family circumstances permitting.
• Gain entirely non-QSBS (stock not section 1202-eligible, partnership interests, asset sales). Full New York tax applies. Relocation provides the largest savings.
• Asset sale involving NY real property or NY-located tangible personal property. Even non-residents owe NY tax on the NY-source portion. Relocation cannot eliminate this layer; structuring as a stock sale (rather than asset sale) of the holding entity can.

The audit posture: stricter than most expect

The New York Department of Taxation and Finance audits residency changes aggressively, particularly for taxpayers reporting large one-time gains in the year of a claimed domicile change. The audit looks for:

• Continued maintenance of a New York residence (apartment, brownstone, second home)
• Continued business activity physically conducted in New York (board meetings, office use, business networking)
• Children remaining in New York schools
• Spouse remaining in New York
• Time-in-NY records from cell phone, credit card, and EZ-Pass data exceeding 90 days during the transition period or 183 days for statutory residency tests
• Continued NY professional service providers (CPA, attorney, financial advisor, doctor, dentist)
• Voter registration, driver's license, and other government records continuing to show NY

New York's audit process is more administrative than California's but similarly aggressive in the evidence it gathers. Practitioners advise the same 6-12 month relocation discipline as for California-to-Texas moves: sell or lease out the NY home at fair-market rent to an unrelated party, move the family, change all professional service providers, limit NY time to under 90 days per year during transition and under 30 days afterward, and document everything.

NYC-specific considerations: the city tax adds 3.876 percent

New York City residents pay both NY state and NYC personal income tax. The NYC PIT applies on the same worldwide-income basis as state tax for NYC residents — there is no separate NYC source-income rule for non-residents (NYC has no PIT on non-residents). For founders relocating, this means changing domicile out of NYC eliminates the city tax in addition to the state tax.

A NYC founder relocating to a NY suburb (Westchester County, Long Island, Fairfield County CT) saves the 3.876 percent NYC tax but still owes the full NY state tax. A NYC founder relocating out of state entirely (to Florida, Texas, or another no-tax state) saves both. The two-step planning option — move to a NY suburb first to save NYC tax, then relocate further if the state tax savings justifies it — is sometimes used for founders unwilling to make a full out-of-state move.

The UBT and pass-through entity considerations

NYC imposes the Unincorporated Business Tax (UBT) at 4 percent on unincorporated business income earned in NYC under NYC Administrative Code section 11-503. For founders selling partnership or LLC interests where the underlying business operates in NYC, the UBT may apply to the gain at the entity level — and this layer is independent of the seller's residency status. UBT applies based on the business's location, not the owner's residency.

For a Manhattan-based LLC member selling their interest, the combined New York tax stack on the gain can include:

• Federal LTCG plus NIIT: up to 23.8 percent
• NY state PIT: up to 10.9 percent
• NYC PIT: up to 3.876 percent
• NYC UBT on the partnership interest gain attributable to NYC: 4 percent
• Combined: approximately 42 percent on amounts above all thresholds

Stock sales of NYC-based C-corporations avoid the UBT layer because the UBT applies only to unincorporated businesses. This is one of the entity-choice considerations for founders setting up businesses in NYC who anticipate a future sale.

Key takeaways

• New York taxes residents on worldwide income at up to 10.9 percent state plus 3.876 percent NYC for Manhattan residents — a combined top rate of approximately 14.776 percent that matches or exceeds California for high-income founders.
• New York's domicile-and-statutory-residency framework under section 605 catches taxpayers who maintain a NY apartment and spend significant time in NY even after changing domicile. The 183-day statutory-residency threshold (partial days count) is a hard trap for relocating founders who keep a pied-a-terre.
• New York conforms to QSBS Section 1202. New York-resident founders selling QSBS-eligible stock within the $10M federal cap pay $0 state tax on the excluded portion. This is a major planning lever that California does not provide.
• Non-resident sourcing under section 632 treats stock and partnership interest sales as non-NY-source for genuinely non-resident sellers. A founder who actually changes domicile to Florida or Texas 6-12 months before a stock sale of a NY-operating C-corporation pays $0 NY tax on the gain.
• The 548-day rule has limited utility for ordinary US-domestic relocations. Practical relocation requires documented domicile change through the standard multi-factor analysis: move the family, change driver's license and voter registration, sell or lease out the NY home, transfer professional service providers, limit NY days.
• On a $15M founder exit with $10M QSBS-eligible and $5M non-QSBS gain: staying in NY/NYC costs approximately $677K in state-plus-city tax; relocating to Florida 12 months pre-sale eliminates that entire amount. The relocation savings scales linearly with the non-QSBS portion of the gain.
• Installment-sale recognition under IRC section 453 creates timing flexibility — installments received after a documented relocation can be sourced to the new domicile state for intangible-property gains. This is a fallback planning option for founders who cannot complete a full pre-sale relocation but can document a post-sale domicile change before later installments.
• The NYC Unincorporated Business Tax adds 4 percent on partnership-interest sales of NYC-operating businesses regardless of seller residency. Stock sales of C-corporations avoid this layer; this is one of the entity-choice considerations for NYC founders.