Determining sequences of queries for retrieving images of negotiable instruments such as checks. A request for a check image is received from a first computer such as an account holder computer at a second, intermediate computer that hosts an on-line banking program and is in communication with a third computer of a financial institution. A sequence program is executed to determine a first sequence of queries having respective query formats available to attempt to retrieve the requested image from an image server or data store. The first sequence is determined based on historical data of whether respective query formats were successfully used in the past to retrieve respective requested images from the data store and is dynamically updated to reflect whether queries were used to retrieve requested images. Thus, with embodiments, the order of queries to utilize is dynamic and can change as opposed to being pre-determined or static.