@TomD8 wrote:
A bonus you receive for work you actually performed in Massachusetts is fully taxable by Massachusetts regardless of where you live.
Right, but in the present case, it appears the taxpayer will continue to work for the same employer, in a different location, and will be paid a bonus at the end of the year. In that case, the bonus is proportionally taxed by Massachusetts. If I misunderstood, and the taxpayer is also changing employers, and the bonus only represents work performed in Massachusetts, then it will be fully taxed in Massachusetts (and California).
