It is necessary to mention the postal Code while you send a letter or a parcel via the Peru postal system. The postal Code numbers literally route the post you send through the geography of Peru to the address given in Las Gramas, San Antonio. In fact the actual address is read only at the final post office where they do the final sorting for delivery. Thus Postal or PIN code helps post offices to speed up the sorting and delivery of mails. postal Code is also otherwise called as postal Code or PIN code (Postal Index Number).