If you’d like to merge two lists that have different fields (when you try to merge a list created in the old version of Benchmark Email with a list created in the new version, for instance), you need to follow these steps:

1. Go to the source list.
2. Click on "Download Excel" and save the file on your computer.
3. Click on "Add Contact" from the List Menu.
4. Click on the "Import Contacts from File" option and click on "Save & Add Contacts"
5. Select the target contact list. Click on "Save & Next"
6. Now upload the excel file from your computer and click Upload
7. Map the fields in the target contact list, click on "Save & Next". Provide the details about how your compiled your list
8. Click on "Save & Next". This should merge your lists.

If you follow the steps above, you can merge an unlimited number of lists with any target list of your choosing.