Often mistaken for an advertised scam, this bill is real.
All new homeowners receive a supplemental tax bill, separate from all other property tax bills within 6-12 from the date of the home purchase. Since this bill is only generated once, it is sent directly to homeowners for payment. Even if monthly mortgage payments contribute to an impound or escrow account and the mortgage company pays the property taxes directly, homeowners are still responsible for paying this supplemental tax bill separately. In most cases, mortgage companies will not even receive this special bill.
Here is the tax assessor’s brief video on how this special bill is calculated as well as a more detailed description.