Microchips are a good back-up option for pet identification, but should never be the main one.
Reading a microchip takes a special scanner, one that an animal control officer or shelter will have, but your neighbor down the street will not.
An animal shelter or vet clinic that finds your pet can contact the registry to get your name and phone number.
Some companies charge a one-time registration fee while others charge an annual fee.
You need to contact the company that registers the chip to update your information; otherwise, the chip will be useless.
You may be charged a small fee to process the update.
And if Fido wanders off, it's likely to be a private citizen who encounters them first.
That's why, in the event of accidental separation, identification tags are your pet's first ticket home.