The Assessor Parcel Data eService provides information about a parcel. The information is based on your Fee Parcel number. The information provided is intended for personal use only. For questions about this eService please contact the Napa County Assessor. Directions: For residential property you can search either by parcel number or address. To search by parcel number enter the parcel number either as 002152012000 or 002-152-012-000. To search by address enter the street number and then the street name - for example 1917 First. You do not need to enter the entire street name or the street type - for example 895 Howell Mountain Road can be entered as 895 Howell.