Does anyone know whether an endorsement on breeding can only be applied on registration of puppy.. Or can it be placed at a later date. I feel so stupid. I let a close friend of mine have her puppy and after mu h pleading she persuaded me to leave the endorsement out.. I  knew she was a competent experianced breeder who extensively health tests... She now has a  new partner and his ethics are not good so i now no longer trust her as much as i have allways done.. I could really kick myself as i endorsed my own puppy and the other 4...Just feel sick at my stupidity

You can only place the endorsement when the puppy is in your ownership.  If your friend has taken the puppy, I'm afraid its too late.
I always place endorsements until such times as health tests are complete

Yes the puppy has to be in your physical possession, not just still registered in your name.

Endorsements can be placed at any age, butonly by the registered owner who has physical possession of the dog.