To provide an invoice (or estimate or delivery card) creation system which allows operators to easily create an invoice according to a specified invoice document (or estimate or delivery card) different for every client, and improves the efficiency of paperwork.

The invoice creation system has an invoice (or estimate or delivery card) pattern storage means for storing multiple types of pre-patterned invoices (or estimates or delivery cards), an invoice (or estimate or delivery card) pattern selection means for selecting an appropriate invoice (or estimate or delivery card) pattern from multiple types of invoice (or estimate or delivery card) patterns stored in the invoice (or estimate or delivery card) pattern storage means based on inputted information, and an invoice creation means for creating an invoice (or estimate or delivery card) based on the invoice (or estimate or delivery card) pattern selected by the invoice (or estimate or delivery card) pattern selection means.