The American Animal Hospital Association has a microchip lookup tool online. Enter the chip number and the tool lists whose chip or registry is associated. Please use THAT registry for your chip. That is the one that will be searched by whoever finds your pet and scans the chip. Many of the registries advertise that you can register anyone’s chip on their registry. However, if my scanner, combined with the AAHA lookup tool tells me you have an AVID chip, I won’t be searching the HomeAgain registry for your contact information.