To obtain an article sales registration data processor which can perform a discount process by an M and M system in a specific period with simple constitution.

The sales quantity of bulk sale constituent articles after sales registration processing by a sales registering means is counted corresponding to bulk sales information (step S4) and when it is decided that the counted sales quantity satisfies a bulk sales establishment quantity (Y at step S6), a discount process is performed according to discount information stored in a bulk sales condition storage means corresponding to bulk sales information on the established bulk sale (step S7). When it is decided that the counted sales quantity does not satisfy the bulk sales establishment quantity (N at step S6), holdover data is generated on the basis of bulk sales information on bulk sale in failure and the sale quantity made to correspond to the bulk sale information (step S9) and the handover data are symbolized as code to print and issue a discount assisting ticket (step S12).