Yes, I have a registered one too!! Did not want to, due to extra paper work etc. but when I counted up (roughly!) I reckoned I had a third over the 50 you are supposed to have before registering ......I did mine over the phone, and a lot of the questions asked were not relevent to my hen set up.
I suppose if there is an outbreak of any bird virus, they know where to come......but it can still affect those with under 50 birds too, surely!!!