Conference add controls can be used to place the user, their current call and any calls they have on hold into a conference. When used to start a new conference, the system automatically assigns a conference ID to the call. This is termed ad-hoc (impromptu) conferencing.

If the call on hold is an existing conference, the user and any current call are added to that conference. This can be used to add additional calls to an ad-hoc conference or to a meet-me conference. Conference add can be used to connect two parties together. After creating the conference, the user can drop from the conference and the two incoming calls remain connected.

For further details, see Conferencing.