mini splits in Yonkers..do we really need a permit? What about a expeditor?

I'm continually getting mixed answers from every professional involved with the job (and neighbor who lives in the area). Anyone have experience adding mini splits to their abode, and if so did you get the proper permits.

Add on question - did you do all the permit pulls yourself, or use "an expeditor"? An illusive title that just means someone who knows how to navigate the permit process. We've been given the name and number of a few but can't tell if its worth it. What we have heard again and again is that Yonkers has such a difficult permit process.