When you got Milly and Molly, you would send the movement sheet to your local animal health department at the council. I know our council do not inform DEFRA that you have the goats, not sure if thats the case with all. You are supposed to tell DEFRA that you have bought some goats. They send you a lot of info, and a big folder to list all your goats etc. in. Every year they do a survey of all the goats in the country and we fill a form in and send it back. All I have is a letter confiming I keep goats at this holding number.
I assume you will have a similar system in Wales.