What is the prefix for planned?

There isn't a single, common prefix for "planned". However, depending on the specific nuance you want to convey, you could use prefixes like:

* Pre-: indicating something done beforehand, as in "pre-planned".

* Pro-: indicating something done in advance, as in "pro-active planning".

* Fore-: indicating something planned ahead of time, as in "forethought" or "foreplanning".

Ultimately, the best prefix to use depends on the context and the specific meaning you want to convey.