Tags on Service Managed IP

This wasn't much of an issue before the price changes around Public IP usage since there were no separate charges. I have several "Service Managed IPs" that are related to Site to Site VPNs. I need to Tag those IPs with a Cost Tag. The Site to Site VPN is tagged correctly but that Tag doesn't apply to the IPs that its using. I also attempted to use the IP Address Manger to Tag the Service Managed IPs. However, the Tag tab is shown but doesn't have any way to actually add a Tag. The charges for those IPs are falling into the Untagged group now because I'm unable to Tag them. Anyone know how I can get those IPs tagged? Thanks in advance.