Legal Question in Credit and Debt Law in California

It depends on the agreement you have with that someone. If the agreement is not in writing then you might have problems if you sell the property and then that person claims you had a different agreement. Also, it depends on the property since some property require you to file a lien and register it with a government agency to have a valid lien on which you can execute, such as the Secretary of State or DMV. The word collateral is too general to really answer your question with any degree of accuracy. Be very careful about selling someone's property unless it is absolutely clear that you have the right to do that... You might need a court order.