When you paste a list of customers, products or what ever into the Paste window remember to click the Validate button! Then check at the top of the window – if there were any invalid entries they will not move to the box on the right side, the will remain in the box on the left, above that in red will be a notification on how many entries were invalid. If any of the entries were dups you’ll also get notified and only one entry for each duplicate will get copied.
