Hi,
Thank you for posting your query on Symantec community.
When the license goes out of compliance the Symantec Endpoint Protection product goes into enforcement mode. There are two types of enforcement
1) Hard Enforcement: Applies to SEP 12.1 Small Business Edition , it blocks all the updates from Liveupdate Server.
2) Soft Enforcement: Applies to SEP 12.1 Enterprise Edition It does not block any updates from Liveupdate Server.
In short if it's Small Business Edition clients will not receive any updates, if it's Enterprise Edition SEPM & clients both will receive updates. You should be able to renew the licenses better call Symantec license team & they can guide you further.
Refer this guide also:
Licensing enforcement rules
http://www.symantec.com/docs/HOWTO80852