Address numbers are required per the Sonoma County Fire Code. Only Permit Sonoma is authorized to assign an address numbers to a parcel in the unincorporated area based on very specific criteria. Sometimes an address number is not available due to sequential order and availability. This will be the only time a letter will be used, as an example, 1234 B. The letter A is reserved for the primary unit. An example is, if you have a Single Family Dwelling (SFD) and the number is 1400 the Junior Accessory Dwelling Unit JADU will be assigned 1400 A.
Address numbers are also assigned to commercial development. The individual office spaces or units will get a suite number. Example, 2300 is the building and the units will be suite 100,101,102.
Email permitsonoma-addressing@sonoma-county.org to request an address.