About inviting groups to calendar events

Inviting a group to an event is the easiest and most efficient way to invite substantial numbers of people at one time. Using groups, you can invite up to 10,000 attendees for one-time events and 5,000 attendees for recurring events.

Events with more than 200 guests (including rooms) are handled a bit differently, as described in the last section below.

What happens when I invite a group?

When you invite a group and you have permission to see the group's members, the group is added to the event as a special type of guest, as indicated by the group icon:

You can check group members and their responses by clicking the small arrow next to the group’s name.

The event’s guest list will keep up with changes to the group’s members: the event will appear for new members of the group and will be removed from the calendar of people that leave the group (unless they are invited directly or as a member of a different group).

A few things to note:

  • Event guests will also see the group name in the event. Their ability to see group members and responses depends on their access level to that group.
  • If the group A contains another group B as a member, then group B will be shown in the event as nested inside group A. You’ll be able to see members of group B only if you have appropriate access permissions.
  • Changes in a group’s membership are usually reflected in your calendar within half an hour, but it can occasionally take up to 24 hours.
  • If you click the Expand group link, the group expands into a list of guests who can be individually removed. However, group membership information is lost, and the event will no longer keep up with group membership changes.
  • Group changes are only updated for events that haven’t happened yet, including future instances of recurring events.
Automatic group updates work only for groups added to an event after the feature was launched in November 2013. To make group updates work in an event that was created earlier, edit the event as follows: remove groups from the guest list, add the groups again, and save the event.
What happens if the event’s organizer or an invitee doesn’t have permission to see group members?

Whether you can see a group's members list depends on the group’s View Members access setting. For example, some groups allow only owners and managers to view the members list, in which case only those users can expand the group's list of members in calendar invitations.

If the meeting organizer doesn’t have permission to view group members:

  • The event will not keep up with group membership changes.
  • You won't be able to see the list of members, their schedules, or their invitation responses.
  • Group members receive an invitation sent to the group address that they can't accept directly (but that they can add to their calendars, as described below).
How can group members accept calendar invitations?

When a group is added to an event, group members receive email invitations if the event organizer opts to send them. When new members join the group, they will get email invitations for all events the group is invited to, regardless of whether the organizer initially opted to send invitations.

If the organizer can see group members, it's as if each member of the group was invited individually. Members can accept the invitations as usual with the Yes, Maybe, and No links in the invitation.

If the organizer can’t see group members:

  • The event is not automatically added to members' calendars. Events are only added to attendee calendars when they are explicitly listed in the invitation's Who list.
  • Group members can't reply with Yes, Maybe, and No links. (They will see an error message if they click these links.) Instead, members can click Add to calendar in the top section of the invitation.
How are large events (>200 guests) handled?

When a group invitation expands to over 200 guests total, including members of all groups and rooms, but excluding duplicates, these restrictions take effect:

  • The invitee list will stop keeping up with group membership changes.
  • Invitees do not see the full invitee list.
  • Invitees can never modify the event or invite additional people to the event.
  • Responses are not sent back to the event organizer, and RSVP status will not appear in the event details.
  • The event organizer will see a warning in their calendar if an event exceeds 200 guests.
  • The event can't be transferred to another organizer or moved to a different calendar.
How is the 200 guest limit calculated?

Guests are counted by distinct email addresses in the guest list, including all rooms, previously invited guests who have been removed from the guest list, expanded group members, and each group itself.

For example, suppose you have an event that consists of an organizer, a directly-invited guest (Guest1), a group that contains a single member (Guest2), and a meeting room.

Let’s say the organizer removes Guest1 from the event. The organizer can see that the event now has 2 guests (Organizer and Guest2) and a Meeting Room, but the event actually contains 5 emails that count toward the 200 guest threshold:

  • Event Organizer
  • Event Guest1 (even though the guest has been uninvited)
  • Invited Group
  • Single member of the group, Guest2
  • Meeting Room

Because an event “remembers” all guests that have ever been invited (directly or via groups), even if they have been removed from the guest list, it might surprise the organizer when an event exceeds the 200 guest threshold.

For example, if many guests have been removed from an event over time, adding even a medium-sized group of 80-100 people could bring the event above the 200 guest threshold, and the limitations described above will apply. When this happens, the organizer will see a warning in his or her calendar that the event exceeds the threshold. The workaround for such a situation would be to recreate the event.