Need to file a mechanics lien in Contra Costa County? Here's what you need to know to record your lien with the Contra Costa County Recorder.After full payment of defaulted taxes against which a certificate of lien has been recorded, an Unrecorded Release of Lien notice will be mailed to the owner. Lien – An encumbrance which makes property security for the payment of a debt or the discharge of an obligation. How do I obtain information on Tax Lien Certificate Sales? The Contra Costa County Treasurer-Tax Collector does NOT offer tax lien certificates. 18. When a lien is placed on a property, it encumbers the property. It means the owner cannot legally, sell, refinance, or transfer a clear title of ownership. This means that if the claim is assigned, the buyer cannot sue in the small claims court. One of our area's most famous bankruptcy filers sang that line over thirty years ago, and it is even more true today.