A few years ago our dog got out (Stupid power company went though our back yard and opened our gate and let the dogs out). We put up signs and were looking for him. Someone took him to the vet to get him checked out and told the vet he had the dog for years and was just able to afford to take him in to get checked out. The vet scanned his chip and our information came up. They called us. The guy left the vet and left our dog there. He is a purebred pekingeses.

That is why it needs to be inside the animal. And yes that is a true story. And yes he was also wearing a collar with a nameplate and address on him, the guy replaced it with a different collar.

Yes. The this is the alternate way of doing it with the RFID flaps if for some reason your pet doesn't have a chip or there are issues reading it. Cats can lose collars though, many have a release mechanism so that if the collar gets caught the cat doesn't get stuck forever too.

https://www.surepetcare.com/en-gb/accessories

Collar, yeah. How bad is an RFID chip though?

If a collar sits comfortably on a cat's neck, the cat will remove the collar. If a collar sits very tightly on a cat's neck, it's somewhat uncomfortable.