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South Carolina · rsu tax

RSU taxes in South Carolina: withholding, supplemental wages, and state nexus

How South Carolina's 6.2% top marginal rate interacts with supplemental-wage withholding on RSU vesting, and what to do when your RSUs vest after a move.

What South Carolina residents actually pay

South Carolina taxes ordinary income at a top marginal rate of 6.2%. RSU settlement value, NSO exercise spread, and ESPP discount income all count as ordinary wages for this purpose and flow through the state's normal brackets.

44% long-term cap-gains exclusion.

Withholding gap

Federal supplemental-wage withholding on RSU vesting is flat — 22%, rising to 37% once year-to-date supplemental wages exceed $1M. If your actual marginal rate is higher, the shortfall shows up at filing. In South Carolina, layer on 6.2% at the top and model what you'll owe before year-end.

Sourcing when you move

If you earned part of a vesting tranche while in a different state, most high-tax states (California, New York, Massachusetts) use workday allocation between grant and vest. Your payroll will likely withhold only for your current state, so a manual true-up at filing is the rule, not the exception.

Frequently asked

Does South Carolina tax RSU income the same as wages?
Yes. South Carolina treats RSU ordinary income as wages, taxable at the state's top marginal rate of 6.2%. Supplemental-wage federal withholding (22%, or 37% above $1M YTD) does not adjust for state withholding, so you often owe extra at filing.
What happens if I exercise ISOs while living in South Carolina?
South Carolina does not run a separate state AMT, so only federal AMT applies. You still need to model the bargain element carefully if you plan a cashless exercise-and-sell.
I moved to South Carolina from another state. Who taxes my vesting RSUs?
Most high-tax states (CA, NY, MA) source RSU ordinary income to workdays between grant and vest. If your grant pre-dates your South Carolina move, expect the old state to tax the portion of each tranche attributable to workdays earned there. South Carolina taxes the remainder.
Can I reduce South Carolina taxes by timing my RSU sales?
South Carolina gives preferential treatment to long-term capital gains. Holding RSU shares 12+ months past vest can produce both federal and state savings. Weigh concentration risk before using this as a reason to hold.

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