I know the that the idea of doing hair extensions without a license is a controversial subject and the CA State Board of Cosmetology is not really clear in their rules and regulations about what they allow or disallow.  So I sent them an email and here's the response:

 

Thanks for the update on the rules and regulations. I was wondering if and when the State Board was going to jump on this...

I always thought that working on someone else's head required a license. After reading their rules, I can see it is about chemical applications.

 

 

Sofiaone, that's what it sounds like the State Board of CA says that someone can do legally without a license, braiding, weaving, and micro rings.  I think shrink links would be considered an adhesive.

 

The State Board didn't really addres my second part of the question though.  I asked them in a unlicensed person can even work in a salon doing hair extensions services.  Normally the State Board inspects salons and believe me, they check to make sure everyone working there has a current license on display at their work station, so I don't know how a unlicensed person would get around that.   I have endured plenty of State Board inspections and usually they are looking at everything with a fine tooth comb.  They want to find violations so they can fine the person or the salon and get revenue for the state.