For England & Wales (and probably Scotland as well)
1. Agree that buyers should register in the system first, whilst technically the seller can register them , this has created issues in tying up previosuly, and I don't trust the database to match it all up.
2. The buyer needs to give the seller two bits of info for them to find them in the system. However the system doesn't seem to always find them, so we are asking for address, postcode, holding no, herd no. from our customers.