An assessor Parcel Number, or APN, is a unique number assigned to parcels of real property by the tax assessor of a particular jurisdiction for purposes of identification and record-keeping.
To find a home's APN, go to the jurisdictions tax assessor's office website and look for property records. There you can search for your address. After finding your address, the APN, lot size, home type, tax history and sales history should be available.