A method, executed by a processor, for generating a transaction classification rule that can be applied to unclassified transactions. The method includes receiving an identification of an existing unclassified transaction upon which the classification rule will be based; generating identification rules to identify subsequent unclassified transactions as similar to the existing unclassified transaction; generating the classification rule using the identified transaction; and storing the classification rule for application to the subsequent unclassified transactions. Application of the generated classification rule to the subsequent unclassified transactions produces transactions classified according to the classification rule.