Note: Rate groups that have been associated with other entities (rates, rate plans) are in use and cannot be deleted. The delete icon will be greyed out if the rate group is configured on another system entity. If you need to delete a rate group first ensure that the rates and plans connected to it are modified so that they use a different rate group.
Under the Usage Rate Groups heading select the rate group you wish to delete
In the same panel click on the icon
On the confirmation pop-up select Yes