Two of my dogs have HomeAgain chips. My new mini poodle has an AVID chip. I did register her through HomeAgain too. I was told that when the chip is scanned it will look like an AVID chip because of the 9 numbers, but most shelters and most vets would either call Avid AND HomeAgain or they would look up the chip at
Pet Microchip Lookup - Powered by AAHA to see where that chip was registered so they know which company to call.
Our local shelter also keeps microchip information in their own registry that they share with surrounding cities including those in CA. The shelter also matches chip numbers to rabies license numbers. They also ask you to send them a picture of your dog to keep for their files.
I called HomeAgain and I asked about this scenario and they refer people calling in with a non HA registered chip to
Pet Microchip Lookup - Powered by AAHA and to the other pet registries like AVID. They say that AVID and other registries have done the same for them.
I'm fairly certain that most vets and shelters would do their due diligence and call more than one pet registry or use the chip lookup system to find out where a chip was registered. It's not like there are a couple dozen major microchip registries out there.
I have looked up all of my pets' microchips, and the chip lookup system works very easily. You just have to type in the chip number in a little box and hit submit. The HomeAgain logo and phone number popped up, and it will also say when the last time I updated the microchip information.
HomeAgain doesn't make you register each year. You have to do it only once, but you can pay yearly for the upgraded membership that has added benefits. You can change your contact information and pictures anytime at HomeAgain after the first time your register. There's no fee for changing your information and pictures no matter how often you do it.