There is noting like phone licenses compatible with CUCM versions. you are licensing the CUCM server and not the phones.
With old license model, the license where based on the version. with new flex licenses they agnostic means its not version dependent.
You haven't mentioned what version of CUCM you use. if its ELM,PL you can see the licenses with version mentioned. If its 12+ you will see the licenses on smart account. for old licenses it will show version and for new you wont see any version.
