How to report on the number of subscription Licenses used per each location

[EJ Liggieri]

We have one company and about 20 locations which are financially separate entities with many Microsoft 365 subscription licenses. i.e. Kiosk, Business Standard, Apps Only, etc.... 

How can we create a report to generate a report that provide a total count for each subscription by location?  An comma delimited file (CSV) is fine.  My initial thought was to use a field, like the Department Field in AAD, or possibly add a custom field to report off of...  

Thanks for the input. 

[#2]

Thought an example might help explain the problem. Total MS bill $10K monthly. Accounting / Finance needs to know how much of that was spent per entity or location in our case. Thanks again.