Under a contention between a copy job and a print job, it is possible that a general user misunderstands that the payment he has made for the copy job is mistakenly used on the print job requested by another user. One solution to avoid such undesirable possibility is to display information indicating that the billing process is correctly done. Yet, the general user may fail to notice the display. In view of this, a billing and printing system prevents occurrence of job contention as long as the balance of payment made by a general user remains. An MFP included in the system does not accept any print job if a balance of received payment remains, and does not accept any payment if there is a queued print job.