You can change the customer on a sales order if you have not created any subdocuments for the order (proforma, delivery note, invoice, return authorisation, credit note).
You can also change the order type from wholesale to consignment or from consignment to wholesale, if you have not created any subdocuments for the order.
You cannot change the order type from Wholesale/Consignment to Retail as tax calculations are different. You'd need to copy a Sales Order instead and inactivate the original Sales Order:
From the list view, search for the Sales Order and click the SO number you wish to change
Click [Actions] dropdown and select [Change Customer/Type]
Select the new Customer and click [OK] to confirm
The system will update this Order with the new Customer details
Click [Save]
Change the Type and click [OK] to confirm
