Last Name at Birth for illegitimate child

Question

I have a profile for an ancestor who was born illegitimate. The name of the father is known, but was not acknowleged until his (the father's) deathbed confession, The profile currently has the father's surname as the LNAB. Should this be changed to the mother's surname, and the father's as current last name?

Answer 1

If I understand correctly, he was known as Peter Ludwig Haaf. How old was he when his father died? Did he or his mother then change is last name? If yes, then his LNAB should be Haaf as you suggested. Make sure to explain the change of last name in the biography as you have done here.