Hi I was given one name by my bris, and when it came time for my bar mitzvah the Rov thought it was to modern of a name (the name was Tom) and suggested to switch it. Now I go by Daniel, and only by Daniel that’s how I get an aliyah etc. For the kesubah, what should be written? Tom is not used at all it’s only a legal name.
A person has ownership over his name so therefore if he decides to drop a name and adopt another name he is entitled to do so. If the fist name is not used at all it is forgotten and dismissed. If the original name is still used as a legal name i.e in a passport etc there is a dispute amongst the poskim in hilchos gittin if the name is written in the get. For a kesuvah one does not have to mention it.
Beis Yosef E:H 129 quoting Teshuvah Ashkenazis and Kuntrasim, Ramoh E:H 129:18, Beis Shmuel 129:31 &36, Pischei Teshuvah ibid 54, Sdei Chemed Maareches Gittin 41:4, Teshuvas Minchas Yitschok 7:117.