A method for identifying payment forms accurately identifies types of forms without adding special form identification data. A payment form discrimination method for discriminating payment forms which state a payee account number and a payment amount includes a step of acquiring an image of the form, a step of making a search for the payee account number in the image in accordance with an account number searching rule, and a step of discriminating the type of form based on the searched payee account number. Types of forms can be identified accurately and fast without adding special form identification data, because the form identification is performed using easily searchable account numbers.