Your Guide to California Preliminary Notices in 2020 COMMERCIAL: Upfront Notice: Preliminary 20-Day Notice: Required to be sent within 20 days of first delivery to the owner, general contractor, and lender. If sent later than 20 days, it only covers work done 20 days prior to mailing the notice. Follow-up Notice (if not paid): There … Continue reading California Mechanic’s Liens & Notices