My employer withheld California tax on restricted stock grants for me exactly as described here when I moved out of California years ago. Other states even hav

My employer withheld California tax on restricted stock grants for me exactly as described here when I moved out of California years ago. Other states even have forms for you to submit this calculation to them, see for example New York's IT203-F Schedule B. But you still have to apportion the income between states like this whether there's a form to do it on or not.