I spent a good part of yesterday fighting with a local tax entity. An ex-client got a local bill from 2015, who wanted taxes from the time the guy lived in CA, and outside the local jurisdiction. We had sent proof the guy moved in to the local jurisdiction in September 2015, and out in January 2016...but they weren't buying it. They cashed the check for the actual liability, incurred during those four months, and returns claiming zero liability for the other years.
They didn't care.
They took the position my taxpayer was just making those claims to get out of the tax bill...even though the address they had as of the 2015 filing was out of their jurisdiction, and they sent the bill to that same address. We went back and forth, until I reminded him we had part-year returns for both CA and the local state for 2015, so he sent copies at my direction.
They finally backed off.
IOW, we filed returns with our right hand up, swearing we were telling the truth...and despite having no other proof, they simply denied his innocence. They had no proof of his residence (since said proof couldn't possibly exist), but in the new reality, the client is guilty until proven innocent.
In addition, had my client paid the outrageous bills, the local would've chalked that up as a "correct" filing, and not a false positive, because, well, if someone agrees with your incorrect assessment, that's correct, right???
BTW, their statute says the tax commissioner can send out estimated bills if the commissioner HAS DETERMINED the taxpayer has a liability. The local has decided to reinterpret the statute to include "if they might, or if they did in the past". They send out a fake bill, and if the person doesn't file a return to correct them, they take the taxpayer to court for the full (fake) amount due, plus (of course) penalties and interest. And btw, the P&I is 6% per MONTH for the first five months.