An article sales data processing apparatus comprises a first reading unit configured to read an article identification code from a first medium attached to an article, a second reading unit configured to read the article identification code from a second medium attached to the article, a determination unit configured to determine whether the article identification code is the code read by the first reading unit or the code read by the second reading unit, and a control unit configured to separately display, on a display unit, article sales data obtained from the article identification code determined to have been read by the first reading unit and article sales data obtained from the article identification code determined to have been read by the second reading unit.