Hi Tracey Farrar ,
Good day.
Thank you for posting to the Microsoft Community. We are glad to assist.
To add a new participant to a recurring Outlook invitation without sending it to all participants, follow these steps in the desktop version of Outlook:
- Open the invite in Microsoft Outlook.
- Click on “Scheduling Assistant”.
- Click on the “Add Attendees” button (you can also delete attendees at this step).
- The Address Book will appear, allowing you to remove names and add new ones, including optional attendees.
Remember to save your changes after adding the new participant.
I hope this helps let me know if this is contrary to what you need, I would still be helpful to answer more of your questions .
Best Regards
Community Moderator