The United States Service Dog Registry is a FREE Service Dog Registry. Your dog will get his/her own number so that people can look him/her up on the registry to confirm his/her status as a service dog. If you wish to purchase patches, a card or other materials with the registry information on it, this is separate to the SD registry which is free. (I repeat.)
Don't pay money to register your service dog! Those registries or "certifications" are a scam. Remember that service dogs do not have to be certified and do not have to belong to a special registry. You do not have to show anyone any paperwork. This is the law!
Never pay money for a service dog certification program that does not train dogs and has never met you or your dog. These certifications will not hold in court! Do not pay for your service dog to be put on a registry. Just make sure that your service dog meets the definition of service dog given in your state law and especially in federal law (ADA).
Make sure your dog can perform about 3 tasks that mitigate YOUR disability meaning it is something that YOU cannot do on your own, and that you know what they are. Do not teach your dog tasks that you do not need him/her to do for you unless you are doing so for the fun of it.
Tasks and work is the same thing. Do not let anyone tell you that they are 2 different things. At this time, the ADA uses the wording that includes both "Tasks and Work" in its definition of service dog (animals).