When do you start applying to transfer?

I’m going to CCC and plan on transferring to a UC. I’ve heard that it takes 2-3 years to be able to transfer, but I want to do it in 2. Let me just state a scenario: say I have 45 transferable units after my Fall semester as a Sophomore, do I start to apply to UC’s as I will complete my other 15 units Spring semester? Or do I have to complete 60 transferable credits before I start to apply to UC’s as a transfer student?

You can apply when you know for sure you’ll reach 60 transferable by spring

Plus all the major requirements needed for each UC to which you are applying must be finished by spring. You should also get at least the first English req course completed by fall before you apply and ideally the math req by fall, although last spring term might be ok for math (depends).