Our landlord has not registered our building with the RSO, and therefore does not have a certificate of registration. Is this a defense for eviction? I rec'd a 3 day to pay or quit for being 4 months behind and am trying to find a defense that wil buy me a little time to catch up. If the building is under rent control but it is not registered with the LA Rent Stabilization Board then the landlord cannot legally demand rent, correct? If he registers, can he collect for past due rent that was due during the time he was not registered?