? returning security deposit - CA

[Yvette M.]

Tenant moved out Sep 30, with 5 months remaining on lease.  He didn't pay Oct rent. I don't have a new renter lined up yet.  His SD will cover Oct rent (and damages) and partial coverage for Nov if I don't have a new renter.

I have to do a SD accounting within 21 days.  So wondering if I can withhold the balance of the SD until a new tenant is placed? I would note on the letter "subject to recalculation once the property is rented."

M2M agreements for me from now on.