You are required to enter the propertyâs 13 digit parcel number as well as the owner of record for that parcel. Please note that the fifth digit in the parcel number must be either an underscore or a letter. You can search by either parcel number or the last name of the owner that is listed first on the deed/bill. You can contact the County of Chester Assessment Office at 610-344-6105 if you do not have the parcel number. Once the form is completed a confirmation email will be provided. The charge will appear on your credit card or bank statement: the certification on one line, the convenience fee on a separate line.