My question involves landlord-tenant law in the State of: California

If you google "california rent late fee illegal", you will get that caltenant advocate website, and mumbo jumbo about liquidated damages, and a court case that set the precedent for late fee illegality.
Despite that, the california association of realtors' lease agreements still have a late fee clause.

It's understandable that if a late fee is imposed to punish, it shouldn't be enforced.
However, if I have to waste my time and gas and drive across 3 cities, and serve a 3 day pay or quit notice to the tenant, I deserve compensation as a $20-25 late fee. That is 'damage' right there.
As a landlord, I'm not punishing the tenant. The tenant is punishing me....

Can any lawyers here paraphrase 1671 (d) in layman's terms, and tell me if I can charge a late fee? (I get lost in all the legalese)
Does code 1671 unilaterally outlaw ALL late fees across the board, or does it allow late fees where you can prove damage?

To me, it seems to say- "liquidated damages and late fees are void except when both parties agree that a specific dollar amount of damage has been done.
The offender pays money because there is no other way to fix the problem."

First of all, tenant signed the lease agreement after agreeing the late fee was reasonable.
Secondly, the landlord has to serve notice at his own expense, and the tenant pays for that expense as a penalty.



There is justification for late fees.

If you hired an attorney to serve the 3 day pay or quit, just printing and mailing the 3day notice would cost $60 in lawyer's fees.



1671. Validity of Liquidated Damages Provisions
(a) This section does not apply in any case where another statute expressly applicable to the contract prescribes the rules or standard for determining the validity of a provision in the contract liquidating the damages for the breach of the contract.
(b) Except as provided in subdivision (c), a provision in a contract liquidating the damages for the breach of the contract is valid unless the party seeking to invalidate the provision establishes that the provision was unreasonable under the circumstances existing at the time the contract was made.
(c) The validity of a liquidated damages provision shall be determined under subdivision (d) and not under subdivision (b) where the liquidated damages are sought to be recovered from either:
(1) A party to a contract for the retail purchase, or rental, by such party of personal property or services, primarily for the party's personal, family, or household purposes; or
(2) A party to a lease of real property for use as a dwelling by the party or those dependent upon the party for support.
(d) In the cases described in subdivision (c), a provision in a contract liquidating damages for the breach of the contract is void except that the parties to such a contract may agree therein upon an amount which shall be presumed to be the amount of damage sustained by a breach thereof, when, from the nature of the case, it would be impracticable or extremely difficult to fix the actual damage.