Billing process for printing systems

A method of performing a billing process for the copies or prints produced by a customer of a printing system, the method comprising:

• a) in the printing system, storing product usage data indicating measurement of the actual use of the printing system;
• wherein the product usage data is determined based on actual use of the printing system, including at least one of:
• (1) meter readings;
• (2) paper consumption;
• (3) toner consumption;
• (4) use of a binding sub-unit;
• (5) use of a scanning sub-unit;
• (6) use of a stapling sub-unit;
• and
• (7) use of a shrink-wrapping sub-unit;
• b) in the printing system, locally accessing the memory to retrieve said product usage data;
• c) in the printing system, locally calculating billing data using the retrieved product usage data;
• d) in the printing system, presenting a bill to the customer based on said billing data;
• e) in the printing system, receiving authorization information indicating whether the customer authorizes the billing data, wherein on the condition that authorization information is not input during a predetermined period of time, default authorization information is generated indicating that the customer authorizes the billing data;
• and
• f) if said authorization information indicates that the customer has authorized the billing data, sending an encrypted message from the printing system to a billing service over a network, the encrypted message including information indicating the authorized billing data.