What if someone’s on vacation or has mail being delivered there etc. or comes in once in a while or Airbnb’s it’s much harder to impliment I think than it sound

What if someone’s on vacation or has mail being delivered there etc. or comes in once in a while or Airbnb’s it’s much harder to impliment I think than it sounds. If you're putting the place up on AirBnB more often than not, the unit is not your primary residence and shouldn't be afforded benefits as such. If the goal of a vacancy tax is to increase rental supply, AirBnB does pretty much the opposite. In California, and most of the US, property assessments are done by elected officials on an annual basis. In California the rate of increase is severely capped, but you're free to apply for a reduction if the value of your property decreases. If you're legitimately on vacation (or whatever), apply for an exemption. It's not that complex.