@qbteachmtThanks for the pointer, i will have to look at this.

No, I do not want the Lacerte Client ID, I want the GUID. 

Its a value in the format of {[8chr]-[4chr]-[4chr]-[4chr]-[12chr]}

BTW, the Lacerte Client ID can be duplicated in different tax types, so is not totally unique by itself.  The combination of Tax type and Client ID I believe should be unique.