some little kid has been missing Tiddles for the last few months, the rspca or even a local vets would scan it and know in minutes who it had belonged to if it was chipped. They would also think you were a nice person if you asked them to do this for you in order to put some cat lovers mind at rest.
You hear tales of the cat being lost for ten years and then being found by scanning, lots of pet owners hold onto that shit in hope for years, you could stop that anxiety. Actually the vet would ring them not you.