The number of productive monitored services is used to determine the appropriate subscription level. This number can be found in the top left of the Checkmk interface's Tactical Overview. If it is the case that you operate Checkmk redundantly in a HA-cluster, the services will not be double-counted. Test systems for evaluating Checkmk versions, etc., are also not counted. If multiple Checkmk instances are in use, then the sum of the services over all of the instances in your business is used to determine the subscription level. Standalone or single HA-Cluster: In your monitoring site, under the host on which your site is running, you can find a service 'OMD MYSITE performance', which has a graph tracking the number of monitored hosts and services. Alternatively, you can search for 'OMD' in the quicksearch to find this service. If the agent on the Checkmk server is older than version 1.2.8. the history of the number of services has to be assumed from the "Check Performance" graph. Distributed Monitoring: The graph already mentioned is available for each site. You can add these graphs to a shared, custom graph to get the total number of services over all sites, and then summarize these.