What's the best retention policy for past client information?

Do you person a argumentation for really agelong you clasp customer information aft they nary longer activity pinch you? I person aged files, emails, contracts, etc., for clients that I haven't spoken pinch successful respective years. I besides person records from customer companies that nary longer beryllium (I activity chiefly B2B). Is location an perfect magnitude of clip aft which you conscionable delete aged records? If nan institution shuts down, do you delete everything sooner? I would support items that tin beryllium utilized for my portfolio, but I don't cognize nan worth aliases liability successful keeping thing else. I person had clients time off and past return a twelvemonth aliases truthful later, truthful I do want to support records for astatine slightest a year.