Methods and apparatus for storing trackable actions in a ledger are provided. A computing device acting as a node can receive a notification of a trackable action. The trackable action can relate to a printer-related transaction and/or an entry-or-exit transaction. The node can generate a block hash value using a hash function operating on data that includes at least part of the notification. The node can add a new block to a ledger, the new block including: the block hash value, a reference to a previous-block hash value of a previous block in the ledger, and the data that includes at least part of the notification of the trackable action. The node can receive a query related to the ledger. In response to the query, the node can provide an output that includes information about the trackable action.