How do I archive customer accounts that haven't made a purchase in the last 3 years?

I have multiple customer accounts within the same organization that makes multiple purchases, sometimes by different person within the same department. Amplify that by multiple accounts across multiple years and one organization has 20 accounts under the same customer/organization. There are accounts with last-made purchases dating back to 2009.

How do I mass update customer accounts to any or all of the below inquiries:

1. Archive (invisible/inaccessible customer)
   1. Add "Archive (year)" so that I can differentiate between recent accounts vs old accounts.
2. Archive (visible/accessible to customer)
   1. Add "Archive (year)" so that I can differentiate between recent accounts vs old accounts.