When Double Taxation on Equity Compensation Isn't Actually Fixed by a Credit

Part of Nauma's complete guide to RSU Taxes When You Move States.

The resident credit mechanism described in Resident Credit for Taxes Paid to Another State resolves double taxation in the most common case: moving between two states that both have an income tax. This page covers the cases where that mechanism doesn't apply, or doesn't fully solve the problem — starting with the single most consequential and most commonly misunderstood scenario in this entire cluster.

The Zero-Income-Tax-State Trap

Here is the scenario that catches more people off guard than any other in this area: an employee relocates from a workday-sourcing state — California being the most prominent example — to a state with no income tax at all, such as Texas, Washington, Florida, or Nevada. The natural assumption is that the move ends state tax exposure on any future RSU vests entirely, since the new state doesn't tax income of any kind.

That assumption is incorrect for the portion of equity income already sourced to the prior state. The prior state's claim, established under its own workday-allocation rules (see RSU State Sourcing and Nonresident Equity Taxation), does not depend on the taxpayer remaining a resident, and it is not offset by anything, because there is no mechanism for an offset to run through. The resident credit described in the companion page only works because the new state of residence has its own tax liability to apply the credit against. A state with no income tax has no such liability — there is nothing to credit against, and therefore the prior state's sourced tax is not double taxation that gets "relieved" at all. It is simply owed, in full, on top of whatever (nothing, in this case) the new state charges.

A Worked Example

An engineer is granted RSUs on a standard four-year vesting schedule while living and working in California. Halfway through the vesting period, the engineer relocates to Texas and continues working remotely for the same California-headquartered employer. Using the workday-allocation formula, 55% of a given tranche's value is sourced to California based on workdays performed there before the move.

The engineer, now living in Texas, owes no Texas state income tax on the vest — Texas has none. But California still taxes its sourced 55% share as nonresident income, filed on Form 540NR, exactly as it would if the engineer had moved to any other state. There is no Texas tax to credit the California liability against, because there is no Texas income tax at all. The California tax on that 55% share is not double taxation in the technical sense — only one state is actually taxing that income — but from the engineer's perspective, it can feel exactly like the double-tax scenario the resident credit is supposed to prevent, precisely because no relief mechanism exists to reduce it. This example is illustrative only and does not reflect any specific taxpayer's situation.

The practical lesson: relocating to a no-income-tax state substantially reduces future tax exposure on equity earned after the move, but does not retroactively eliminate a prior high-tax state's claim on equity earned before it, for as long as that equity continues to vest.

The Second Failure Mode: Convenience-of-the-Employer Rules

A small number of states — New York being the most prominent — apply a "convenience of the employer" rule: an employee who works remotely from another state for their own convenience, rather than because the employer specifically requires it, is treated as if they worked in the employer's state for sourcing purposes, regardless of where they physically performed the work. This creates a genuine conflict: the employee's actual state of residence sources the same income under its own rules (often based on actual physical workdays there), while the convenience-rule state sources it based on the employer's location instead.

This conflict is not always fully resolved by a resident credit, because the resident credit is generally limited to the resident state's own tax on income it agrees is properly sourced elsewhere — if the resident state and the convenience-rule state disagree about how much of the income belongs to which state, a taxpayer can end up with a credit that doesn't fully offset one side of the claim, producing real, only partially-relieved double taxation on the disputed portion.

Practical Steps

Given both failure modes above, the practical response is similar: understand which states have a sourced claim on unvested equity before a relocation, not after; keep detailed, contemporaneous workday records spanning any period near a state change; and specifically check whether either the departure state or the destination state (or the employer's state, if different from either) applies a convenience-of-the-employer-style rule, since that changes the analysis meaningfully from a simple workday calculation. For a large, multi-year vesting schedule with a state change in the middle, professional tax guidance before the move — not after the first affected vest — is generally the difference between a manageable filing and an expensive surprise.

What This Page Does Not Cover

This page assumes familiarity with the general resident credit mechanism, covered in Resident Credit for Taxes Paid to Another State, and the underlying sourcing formulas, covered in RSU State Sourcing and Nonresident Equity Taxation.

California Note

California itself has no convenience-of-the-employer rule — its sourcing claim rests entirely on the workday-based formula described elsewhere in this cluster, not on where an employer happens to be headquartered. This means the Texas or Washington relocation scenario above is the primary double-taxation-adjacent risk for a departing California resident, rather than a convenience-rule conflict — though an employee who moves to a convenience-rule state (such as New York) while continuing to work for a California employer could, in principle, face claims from both states under different theories. See Tax-Friendly States for Retirees for the broader tax picture of relocating out of California, separate from this specific equity-sourcing issue.

This article is for educational purposes only and does not constitute legal, tax, or financial advice. Multi-state equity sourcing and credit rules are technical, fact-specific, and vary by state. Always consult a qualified tax advisor before or during a relocation that spans an active equity vesting schedule.