At my employer they withhold taxes from the RSUs themselves as they vest (taxes are withheld at the bonus tax rate using integer multiplication, I believe). E.

At my employer they withhold taxes from the RSUs themselves as they vest (taxes are withheld at the bonus tax rate using integer multiplication, I believe). E.g.: you'll get Math.floor(x * (1-bonus_tax_rate)) shares and will owe no income tax (unless your marginal tax rate is over the bonus tax rate). After that point, you'll only owe taxes on possible capital gains from price at the time of vest to the time you sell.