Case Studies
Detailed worked-example case studies with full dollar math for real-world multi-state tax scenarios.
Case Study: New York to Florida Relocation — The $42,000 Tax Savings and the Audit Risk
A 45-year-old software engineering manager moves from Manhattan to Miami mid-year, keeping his New York employer. Worked math for part-year resident returns, the New York convenience rule, domicile audit risk, and the multi-year savings that exceed $42,000 when structured correctly.
Case Study: California Resident Working Remotely for a Texas Employer
A San Francisco senior product manager works 100% from home for an Austin, TX tech company. Worked math for California state tax, SDI, FICA, and the $14,600 annual savings of relocating to Austin. Includes the contractor reclassification analysis under California's ABC test.
Case Study: Traveling Consultant — Tax Withholding in 6 States During One Year
An Illinois-based management consultant works 220 days across Illinois, New York, California, Texas, Florida, and Massachusetts in a single year. Full multi-state allocation math, the multi-state penalty when non-resident rates exceed the resident rate, and the PEO alternative.
Case Study: PEO vs Direct Payroll — A 15-Person Company with Employees in 5 States
TechFlow Inc. has 15 employees across CA, NY, TX, WA, and MA. Full cost stack for direct state-by-state registration versus a PEO, including SUI wage bases, workers comp, payroll software, HR administration, and the break-even analysis on benefits.
Case Study: $1.2M RSU Vest — Multi-State Allocation, Convenience Rule, and AMT
A New Jersey resident vice president at a Manhattan investment bank has $1.2M of RSUs vest in October 2025. Full math for federal 37% bracket, FICA on $1.45M, New York convenience rule tax at 9.65%, New Jersey 10.75% bracket, the retaliatory credit, and AMT confirmation.
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