Why, oh why, does anyone use the word "headquartered"? A business has headquarters. They are located in a specific city. They are not headquartered there.
This is how English works: "Headquarters" is a noun. It's a place. According to the Shorter Oxford English Dictionary, it was coined in the mid-1600s. "Headquarter" is a verb twisted out of that pleasant old noun just this last century.
But you don't hear people use that active form of the word often, do you? Why? Because it sounds bad. So why use a passive form of a verb that shouldn't even be one in the first place?
I'm not being a fuddy-duddy. Honest. The verbed word sounds clunky. It doesn't save the writer any space. It brings up, at least to me, unpleasant associations with being drawn and quartered.
Just write, "The business has headquarters" in such and such, and all will be well. Trust me.