Need a license to wholesale properties in California?

[Han Oh]

I was talking to an escrow officer and she mentioned that doing assignments of contract or double closings requires one to have a license since they are considered real estate transactions. 

I know that they deal with investors because I found their info from one of the BP forum discussions under recommended escrow contacts. They used to do a lot of these assignments and double closings a few years back, although it has slowed down recently with the hot coastal CA market making it harder for wholesalers to find deals with enough spread to move it to the next guy. 

So, is having a license a requirement specific to CA or is that information inaccurate or am I missing something else?