Excellent comment - especially the concept of nexus. On the subject of multiple employees & multiple nexus locations, I’d say the NFL & NBA would be very interested in advancing the discussions on reciprocity, given the large traveling payroll for games across the country. I certainly don’t envy the lower-paid support staff needing to do multiple state tax returns or the expense of tax professionals to keep it straight.
It is not just professional athletes - NFL & NBA, MLB, NHL, etc., but also actors and musicians who face this as they are taxed in each state in which they perform, i.e. earned income. It has to be a nightmare to track but I would guess there is specialized software to track it.
But I also went to a seminar where the question of salespersons who make sales in multiple states may be subject to state income tax based on the sales they made in each state or even an apportionment of time spent in each trying to make sales. The company I worked for a the time had no practical way of tracking this, so we took the position of taking our chances that it would never come up unless an audit was triggered.
Some years ago I had a phone interview with the Baltimore Ravens for a PR position and while it paid well and had some great benefits, I’m sort of glad they didn’t hire me 😊