Property tax bills are paid in two installments but the bill is mailed out just once. You will receive your tax bill by November 1. If you don't receive the tax bill till November 10, please contact the Collector's office at (707) 565-2281 during business hours. When you will call, you will be required to provide a fee parcel number written on the previous tax bill or the address of the taxed property.

Property taxes can be paid in two installments. The first installment is due November 1 to December 10 till 5 P.M. While the second installment is due February 1 to April 10 till 5 P.M. 

You can also pay all of your tax bill amount in the first installment.

Property taxes depend on market value. You might have made some changes to your property which have increased the market value of your property. That's why the tax increases for this year. 

OR

The prices of properties have increased in your areas which increases the market value of your property and so the tax.