ScopeThe following article outlines how to resolve cases in which a MAC Address already exists in the Manager Portal when trying to add it.RequirmentsSuper User accountRemoving MAC address from InventoryIn case a WLP accidentally deletes a domain with phones added. When re-creating the domain and adding the phones, they would get the message prompting that the MAC address already exists in the Manager Portal. Here are the steps:Go hereFilter the MAC address one by one that was provided from the WLPOnce you have filtered the MAC address, you will notice that it has no domain which is why the WLP cannot make any changes.Click Delete and advise the WLP to try adding the phones againRemoving MAC address from NDPIf deleting the MAC address from the Manager Portal does not delete, you will then have to try via NDP.Hover over Configurations on the top left Click Devices (Phones & ATAs)Filter the MAC address with no colons (:) on the Filters MAC fieldOnce filtered, click the device model of the MAC address and click deleteAdvise the WLP to try adding the phones again