Missouri
The state of Missouri is the perfect example of a place where insurance options for pilots became quite limited because of heavy-handed regulation. The compliance costs were not worth it with such small numbers in aviation. Many companies left Missouri, leading to increased premiums when competitive carriers no longer serviced their clients. This made it up the ladder and now, it appears this has been fixed in the legislature there are/will be more options for insurance buyers again. Missouri asks about my nonresident income on the license renewal.
California
Other states, like California, have historically not had some of the usual transition insurance markets (example: SEL pilot upgrading to MEL) available to customers because those companies just haven't wanted to deal with CA.
For my agency: California had eleventy steps to get set up, but at least they made it transparent and somewhat logical because they needed the money so badly every step of the way.
Kentucky
There's nothing like Local Government Premium Tax compliance in Kentucky. Up to 12% City, 12% County, and mandatory 1.8% State. Yes, you theoretically could have a 25.8% insurance tax rate in KY, or as little as 1.8%. Further, for an aircraft owner, it's based on where the airplane sits, not the client's address. Do you know how much time I've spent for my client's benefit (to make sure they aren't being overcharged on tax) on Google Maps auditing if an airport is in city limits or outside city limits, then going over the Tax chart? And then each line of business has its own tax rate? And for some reason, aircraft are classified as "Inland Marine" on the tax chart.
Massachusetts
I pay a lead-based paint fee anytime I renew my Massachusetts agent or agency license. Along with a $520 annual report to the state every year to say that I exist.
New York
Complete black hole of regulation. And, if you call the state, you get put on hold. I had to file a classified ads in 2 New York newspapers in Albany County giving an address for service of process. Then had to send the proofs to the state along with a $50 check.
Nationwide:
I owe income tax to numerous states just for having revenue attributable to the state. Kentucky? Minimum $175 even if I never set foot in the state. I paid $1 to Indiana one year. Plus $60 or whatever to file.
Some good news:
There's discussion about trying again on a Federal bill that would eliminate nonresident income tax for companies that have a physical presence in a state for less than 15 days.