Org Owners and Org Admins can manage who can invite guests to workspaces in their organization and set a maximum expiration period to make sure membership stays current.
Choose who can invite guests
By default, Workspace Owners and Workspace Admins in an Enterprise Grid organization can invite guests to their workspaces but Org owners can restrict this, if they'd like.
Note: Members who do not have permission to invite guests to your org can still request invitations. When invitation requests are approved or denied, members will receive a message from Slackbot to let them know.
From your desktop, click your organization name in the sidebar.
Hover over Tools & settings, then select Organization settings.
Choose People, then select Manage permissions.
Select Account Types.
Click the three dots icon next to Manage guest invitation requests, then select Edit permission.
Choose who can invite guests, then click Save.
Set a maximum guest expiration period
Org Owners and Org Admins can set a maximum expiration period for guests to determine when their access to Slack will end. Maximum expiration periods apply to guests invited by members, but Org Owners and Admins sending invitations can choose a longer expiration period if they'd like.
From your desktop, click your organization name in the sidebar.
Hover over Tools & settings, then click Organization settings.
From the left sidebar, select Settings, then click Organization settings.
Next to Maximum expiration for guests, click Edit.