14. The non-transitory tangible machine-readable medium of claim 13 , wherein the common invoice data object format uses an extensible markup language format.
14. The non-transitory tangible machine-readable medium of claim 13 , wherein the common invoice data object format uses an extensible markup language format. 15. The non-transitory tangible machine-readable medium of claim 14 , wherein the method further comprises: creating a common invoice data object format comprising at least the essential data elements.