Applies to: the ZWCAD 2015; ZWCAD 2014; ZWCAD 2012; ZWCAD (ITC)
Yes, it is down-compatible directly, which means:
You can use the higher version license code to activate any version of ZWCAD+ or ZWCAD product that is not higher than the license code version, then all lower versions including the one you activated have been activated successfully.
Note: Not include ZWCAD Classic