“I purchased a narrow lot two houses from my house in 2005.(The lot was deeded to a mortuary in 1977 and no property tax was paid after the date of transaction. From the record it seems to me that someone deeded the lot to the mortuary in lien of payment of service. So it is safe to assume that there was no contact between the owner of the lot and the next door neighbor of my lot, in fact I had to track down the trustee who lives in another country). My neighbor whose house next to my narrow lot bought his house in 1998. He constructed sliding iron front gates on track in front of his house sometime after which I am not sure. But it is very likely that was more than 5 years ago. About 8-10 feet of the track is on my property(I have a survey done). And that part of my property has been mainly used as parking space for his cars. Now my question is would it still work if I give notice of permission for him to continue to use it to park his cars in order to prevent a potential claim of prescriptive easement? Now he simply told my surveyor the other day that he believes that portion of my lot is his. If he is successful in claiming prescriptive easement my lot would be unbuildable because it is only 26.4 feet and there is a requirement of two covered parking space in City of Los Angeles, California. Oh, I’ve been on friendly relationship with him and I didn’t object since buying the lot in 2005.”

The answer to your theoretical question is no: Once a prescriptive easement has been acquired, attempting to grant permission has no legal effect. However, given the facts of your situation, it is not clear whether a prescriptive easement has been acquired yet. If it has not, then giving permission cuts off the 5-year period you mention, so it would certainly not hurt to do so.