Abstract: An improved printing system is provided in which the toner or ink printing material is paid for in portions of a the total amount contained in an ink or toner cartridge. Only a portion of the printing material is authorized for use when the cartridge is new, and further amounts of the printing material can be authorized by a user entering into a transaction with a remote central station, which can provide the user with a coded message that may be entered via the printer's op-panel; or the central station can send an authorizing message directly to the printer via a network. The status of the current authorized amount can be stored in the printer's main memory, or on a memory chip located on the cartridge. Users can “pay as they go” to literally pay for the printing material over time or “usage,” in a manner similar to “installment payments.