Extend the Reassign Invoice Customer utility (Modification #1378) to provide the "Copy Special Price data" option. When enabled, this option will review the invoice line items and copy the basic Special Price configuration information from the original invoice "Ship To" customer to the newly-assigned customer. If the "Assign To" customer already has a Special Price defined for a given item then the existing entry will not be changed. Naturally Mod. #1378 must be active in order to use this feature.

 

Related Mod #1378 Reassign Invoice Customer Option