State-source income is the portion of income that a state treats as connected to that state under its own tax rules. A person can live somewhere else and still have income sourced to a state because work was performed there, property was located there, a business operated there, or another state-specific sourcing rule applies.
The source question is separate from residence. It is also separate from federal tax residency and federal U.S.-source income rules. A person who is a federal nonresident alien can still be treated as a resident, part-year resident, or nonresident under a state’s own law, and the state may apply sourcing rules that do not match the federal rules.
State-Source Income Is About the Connection Between the Income and the State
For a nonresident, states generally look for a connection between a particular item of income and activity, property, or business in the state. The payment address, the bank account receiving the money, or the employer’s headquarters does not always decide the result.
| Question | What It Determines |
|---|---|
| State residency | Whether the state treats the individual as a resident, part-year resident, or nonresident under that state’s law. |
| State-source income | Which income items, or what portion of them, are connected to that state while the individual is a nonresident. |
| Federal U.S.-source income | How federal sourcing rules classify income for U.S. federal tax purposes. |
The three questions can produce different answers. For example, a person may be a nonresident of California, work several days in California, and have part of those wages treated as California-source income. The same person’s federal tax residency and federal sourcing analysis may involve different rules.
The Source Test Changes With the Type of Income
There is no single nationwide formula for state-source income. Even within one state, employee wages, contractor income, rent, business income, stock compensation, and investment income may follow different rules.
| Income Type | Sourcing Question That Usually Matters First |
|---|---|
| Employee wages | Where were the services performed, and does the state apply a special remote-work rule? |
| Independent contractor income | Does the state use the work location, the customer’s location, market sourcing, or another service rule? |
| Business income | How does the state allocate or apportion income from business activity inside and outside the state? |
| Rental income | Where is the rental property located? |
| Gain from real property | Where is the property located, including when gain is recognized later under an installment sale? |
| Partnership or S corporation income | What portion of the entity’s income is sourced to the state and passed through to the nonresident owner? |
| Stock options and other equity compensation | What services were performed in the state during the period used by that state’s allocation rule? |
| Interest, dividends, and other intangibles | Does the state generally follow the owner’s residence, or does a business-use exception apply? |
| Retirement income | Does the payment fall within the federal protection for retirement income paid to a nonresident of the taxing state? |
Employee Wages Usually Start With Where the Work Was Performed
For ordinary employee compensation, physical work location is a common starting point. California states that, during a nonresident period, compensation is California-source to the extent services were physically performed in California. Its nonresident guidance also illustrates a workday ratio as one way to allocate compensation when work is performed both inside and outside the state.
Assume an employee has $144,000 of compensation tied to 240 workdays and physically works 60 of those days in a state that uses a simple workday allocation for the payment involved. The workday fraction would be 60 ÷ 240, or 25%. Applied to $144,000, that would produce $36,000 of income allocated to the state.
That calculation is only an illustration. A workday fraction is not a universal state rule. A different method may apply to commissions, equity compensation, deferred compensation, termination payments, business income, or employees subject to a telework rule.
Working in More Than One State Can Split the Same Salary
An employee can have wage income connected to more than one state during the same year. The allocation may depend on workdays, duty days, business volume, or a special statutory method. Travel calendars, work schedules, employer records, and the purpose of particular workdays can matter because the state may require a supportable allocation rather than a rough percentage.
New York’s 2025 nonresident instructions, for example, distinguish ordinary wages from compensation tied entirely to business volume and from items such as stock options, restricted stock, termination agreements, and covenants not to compete. Different allocation methods can therefore apply even when every payment comes from the same employer.
Remote Work Can Break the Simple Physical-Workday Rule
Remote work is one of the clearest reasons not to assume that wages are sourced only where the employee is sitting. Some states generally emphasize physical presence. Others can treat certain out-of-state telework days as source days under a convenience-of-the-employer rule.
New York’s Convenience-of-the-Employer Test
New York continues to apply a convenience-of-the-employer test to certain nonresident employees whose assigned or primary office is in New York. Under the state’s rule, a normal workday at a home office can still be treated as a New York workday unless the out-of-state work satisfies the applicable employer-necessity or bona fide employer-office standards. New York’s 2025 Form IT-203 instructions continue to direct taxpayers to this test.
This means that an employee assigned to a New York office cannot assume that every day worked from a home in another state is automatically an out-of-state day for New York wage allocation.
New Jersey Uses a Triggered Convenience Rule
New Jersey’s approach is narrower. Its law applies a convenience rule to certain nonresident employees who are residents of states that impose a similar test on New Jersey residents. New Jersey also states that the relevant list can change as other states change their laws. The rule therefore depends not only on the employer and work location, but also on the nonresident employee’s home state and whether that state uses a similar sourcing test.
Remote-work sourcing should therefore be checked state by state. A payroll system that assigns wages to an employer state does not by itself establish the final legal source of those wages.
Independent Contractor Income Can Follow a Different Rule From Employee Wages
An employee and an independent contractor can perform similar services for the same customer and still face different sourcing rules. California illustrates the difference. California generally sources employee compensation to where the employee performs the services, while its business-sourcing rules can assign service income based on where the customer receives the benefit of the service.
That distinction matters for consultants, freelancers, sole proprietors, and owners of disregarded single-member LLCs. Physical location may remain relevant to some states, but it is not safe to treat employee workday rules as a universal method for self-employment or business income.
Allocation and Apportionment Solve Different Problems
Allocation generally assigns a particular item of income to a specific state when the item can be tied directly to that state. Rent from a building located in one state is a simple example.
Apportionment divides income from a business operating across state lines under a state-prescribed formula or sourcing method. California, for example, requires certain nonresident individuals with business activity inside and outside California to use its apportionment rules, including market-assignment rules for some service and intangible receipts.
The terms are not interchangeable, and the method used by one state does not automatically carry over to another.
Real Estate Usually Follows the Location of the Property
Real property is one of the more direct sourcing categories. Rental income from property located in a state is commonly treated as income from that state. Gain from the sale of real property is also commonly sourced to the state where the property is located.
California’s nonresident rules provide a useful example. A nonresident who receives rent from California property has California-source rental income. California also continues to source installment gain from a California property sale to California even when payments are received after the seller has become a nonresident.
Suppose a California resident sells California real estate on the installment method, later moves to another state, and then receives another principal payment that includes deferred gain. California’s published nonresident guidance treats the gain portion as California-source because the property sold was located in California. Interest on the installment obligation can follow a different rule.
This is why the date cash is received does not always determine source. The location and character of the underlying property can continue to matter after a move.
Pass-Through Income Can Create State-Source Income Without a Personal Workday in the State
A partner, LLC member, or S corporation shareholder can receive state-source income through an entity even if that owner did not personally perform services in the state during the year. The entity first determines the portion of its income connected to the state under the state’s rules, and the owner’s distributive or pro rata share may carry that state-source character.
California’s rules, for example, address California-source income allocated to nonresident partners, LLC members, S corporation shareholders, and certain beneficiaries. New York’s nonresident instructions likewise include a nonresident partner’s distributive share of New York partnership income in New York-source income.
A cash distribution and taxable pass-through income are not the same concept. A partner can be allocated income for tax purposes even when the timing or amount of cash distributions differs. State withholding by the entity is another separate question.
Stock Options and Other Equity Compensation Can Follow Earlier Services
Equity compensation can remain connected to a state after an employee has moved away. The relevant state rule may look back to the period in which the employee performed services that earned the option, restricted stock, restricted stock unit, or similar award.
California’s published stock-option guidance states that when a nonresident exercises a nonstatutory stock option, California can tax the compensation element to the extent the related services were performed in California. Its examples use the service period from grant to exercise for nonstatutory options. Other equity awards can use different measurement periods.
The grant date, vesting period, exercise date, settlement date, and sale date therefore should not be treated as one event. A move between states during that sequence can produce a state allocation even though the payment or exercise occurs after the move.
Bonuses, Commissions, Severance, and Deferred Pay May Need Their Own Allocation
Not every payment labeled as compensation follows the same wage formula. A bonus may relate to services over a specific performance period. A commission may depend on sales activity or business volume. Severance, a termination agreement, a covenant not to compete, or deferred compensation may point back to earlier employment or business activity.
New York’s 2025 Form IT-203 instructions are explicit on this point. Ordinary wages can use one allocation schedule, compensation that depends entirely on business volume can use a business-volume fraction, and items such as termination agreements, covenants not to compete, stock options, restricted stock, and stock appreciation rights are directed to a separate allocation form.
The label on a pay statement is therefore only the beginning of the sourcing analysis. The period and activity that produced the payment can be more important than the date the money arrives.
Interest, Dividends, and Other Intangible Income Usually Need a Different Test
Income from intangible property, such as ordinary portfolio interest and dividends, is often treated differently from wages and real estate income. In California, for example, intangible income of a nonresident is generally sourced to the owner’s state of residence rather than to California.
There is an exception when the intangible has acquired a business situs in the state. California’s withholding guidance gives examples such as an intangible pledged as security for a loan connected to a California business or a bank account maintained to pay expenses of California business activity. In those circumstances, the business connection can change the source analysis.
The place where a corporation is incorporated or headquartered does not, by itself, make every shareholder’s dividend or stock gain source income of that state. The source depends on the state’s rule for the particular intangible and the way it is used.
Federal Law Limits State Taxation of Certain Retirement Income
Retirement income is not always treated like deferred wages for state sourcing. Under 4 U.S.C. § 114, a state may not impose an income tax on qualifying retirement income of an individual who is not a resident or domiciliary of that state.
The federal statute covers income from listed retirement arrangements, including qualified plans, IRAs, certain annuity and governmental plans, and some nonqualified arrangements that meet the statute’s conditions. It does not turn every payment received after employment ends into protected retirement income.
For example, a pension that falls within the federal definition can receive different state treatment from a deferred bonus, severance payment, or equity award tied to prior services. The legal character of the payment matters.
Moving During the Year Changes Which Sourcing Rule Applies
Part-year residency divides the tax year into periods. During a resident period, a state can generally apply its resident-income rules. During the nonresident period, state-source rules become central.
California’s current nonresident guidance illustrates the distinction: a part-year resident includes worldwide income received while a California resident and California-source income received while a nonresident. Other states define part-year residency and timing rules under their own law.
A move date can therefore interact with several other dates: when services were performed, when an award vested, when property was sold, when an installment payment was received, and when an income item legally accrued. The payment date alone may not settle the result.
Federal Treaty Treatment Does Not Automatically Control State Sourcing
For nonresident aliens, a federal income tax treaty can affect federal taxation without producing the same state result. States are not uniform in whether they follow federal treaty exclusions.
California expressly states that it does not conform to federal law for income protected by U.S. tax treaties in this area. Its withholding guidance says California-source income can remain taxable by California even when a federal treaty exempts the payment from federal income tax. A federal treaty position therefore should not be assumed to resolve the state-source question.
W-2 State Wages, Withholding, and State-Source Income Are Different Measures
Three numbers are often treated as if they were interchangeable, but they answer different questions.
| Item | What It Represents |
|---|---|
| State wages on Form W-2 | The state wage amount reported by payroll under the employer’s reporting process. |
| State income tax withheld | Tax prepaid to a state through payroll or another withholding system. |
| State-source income | The amount determined under the state’s substantive sourcing rules for the income involved. |
New York directly warns nonresidents that the amount of wages allocable to New York is not necessarily the amount shown as state wages on Form W-2. Its instructions require the New York amount to be determined under the applicable allocation method.
Withholding is also not a final determination of source or tax liability. It is a payment mechanism. California’s nonresident withholding materials separately address whether income is California-source and whether withholding is required, reduced, or waived.
Two States Can Both Tax the Same Economic Income Under Different Rules
A resident state may tax income because the taxpayer is a resident, while another state may tax the same income because it is sourced there. That can require separate state calculations even though the income arose from one job, one business, or one property.
States may provide a credit for qualifying tax paid to another state, or they may have a reciprocity agreement that changes how employee wages are treated. Those rules are state-specific. A credit also does not mean that two state returns will always produce identical taxable income, deductions, rates, or final tax.
A Useful Record Depends on the Income Being Sourced
The documents that matter most are the ones that show where the income-producing activity or property was located and when the relevant activity occurred.
| Income Item | Fact That Often Matters | Records That May Help Establish It |
|---|---|---|
| Employee wages | Where workdays were performed and whether a telework rule applies | Work calendar, travel records, employer assignment records, payroll records |
| Bonus or commission | Performance period, sales activity, or business volume tied to the payment | Compensation plan, commission statements, sales records |
| Stock compensation | Service period used by the state’s allocation rule | Grant notice, vesting schedule, exercise or settlement statement, work-location history |
| Rental or real estate gain | Property location and transaction timing | Lease, closing statement, installment-sale records |
| Partnership or S corporation income | Entity-level state allocation or apportionment | State Schedule K-1 or equivalent state statement |
| Business income | Customer market, sales, property, payroll, or another state-prescribed sourcing measure | Invoices, customer records, sales reports, apportionment schedules |
| Retirement payment | Whether the payment falls within the federal definition of protected retirement income | Plan documents, Form 1099-R, benefit statements |
State-Source Income Does Not by Itself Decide Whether a Return Is Required
Finding that income has a source in a state answers only the sourcing question. Filing requirements can depend on the state’s filing threshold, type and amount of income, deductions, withholding, credits, reciprocity rules, tax year, and other state-specific provisions.
The reverse is also possible: a state return can sometimes be relevant because tax was withheld or because a state requires reporting under rules that do not reduce to a simple source-income threshold. State-source income, taxable income, withholding, and filing obligation should therefore be treated as separate steps rather than as synonyms.
Resources Used
- California Franchise Tax Board — Part-Year Resident and Nonresident Guidance — California-source wages, workday allocation, and part-year residency treatment.
- New York State Department of Taxation and Finance — 2025 Form IT-203 Instructions — nonresident wage allocation, special compensation allocation, W-2 state wage differences, and telework rules.
- New Jersey Division of Taxation — Convenience of the Employer Sourcing Rule FAQ — New Jersey’s rule for certain nonresident telecommuters.
- California Franchise Tax Board — 2025 Schedule R Instructions — apportionment and market assignment for business activity inside and outside California.
- California Franchise Tax Board — Publication 1100 — installment sales, changes of residency, deferred items, and California-source treatment after a move.
- California Franchise Tax Board — Publication 1004 — sourcing of stock-option compensation for California nonresidents.
- California Franchise Tax Board — Publication 1017 — nonresident withholding, intangible-property business situs, and California treatment of federal treaty-exempt income.
- U.S. Government Publishing Office — 4 U.S.C. § 114 — federal limitation on state income taxation of qualifying retirement income paid to nonresidents.