the present invention relates to a data processing and retrieval system for use in a self - checkout system utilized in a retail facility . a plurality of customers are provided with a portable data collecting terminal having a bar code reader . once the data is collected using the portable terminal , a record of the session is uploaded to a customer &# 39 ; s data file upon the entry of an authorization code . in the event errors occur during data entry or in the entry of the authorization codes , a customer service desk is provided which assists the customer in completing the transaction .