Legal Question in Landlord & Tenant Law in California

It's the same anywhere, as far as I know - "reasonable" application fees, deposit of not more than two months rent for unfurnished, and three months rent for furnished units, and whatever amount of prepaid rent the landlord wants to demand if the lease is for six months or more. If it is month to month only the first month's rent can be charged. If it is a multi-unit building, they can also charge reasonable service fees for loading dock or elevator access, though normally that is just built into the rent, unless it is a condo with an HOA that charges such fees and the landlord is only a unit owner. The bottom line, though, is the only real legal limit is on the deposit and pre-paid rent on a month to month rental.