Hi Carolee,
There is not a way to copy an invitation list from one event to the other, however you could add the invitation list from the original event to a contact group in your address book. Then, when you create the second event, you can add the entire contact group to your invite list which will save you time in having to go through an entire import process again.
Information on managing contact groups can be found here.
Thank you!
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Erica Kennedy
Principal Client Success Manager
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