Abstract: The present disclosure is directed towards systems and methods for flexible field mapping between disparate systems, which comprises generating a base mapping request comprising a base mapping between a source data object having one or more source data fields and a target data object having one or more target data fields and generating a field mapping request comprising a field mapping between a given source data field and a given target data field. One or more data items are identified from the target data object responsive to the base mapping request and the field mapping request. A combined request is then generated comprising the one or more data items responsive to the base mapping request and the field mapping request. The combined request is transmitted to a target memory. One or more tax values responsive to the combined request are subsequently calculated based on the one or more data items.