(This should not be relied upon for practical halacha. When a question arises a Rabbi should be consulted.)
1. The names of the chosson and kallah are written in the Kesubah. If the names are omitted or written incorrectly, the Kesubah is invalid. (Nisuin K’Hilchosom page 345)
2. Harav Shlomo Zalman Auerbach zt”l, citing the words of the Sefer Nachlas Shiva, maintained that when writing the names in the Kesubah, one must make sure to use the same level of scrutiny as one would when writing a Divorce document. For if the couple ever gets divorced they might end up using the Kesubah as the blueprint as to how to write and spell the names of the chosson and kallah. (Shalmei Simcha page 267)
3. Harav Moshe Feinstein zt”l (Igros Moshe E.H. 178) discusses whether one should add the surnames to the names of the chosson and kallah in the Kesubah. He promotes the addition of surnames. He explains that since it is possible that multiple people in the city have the same name and their parents also have the same name, in order to specify who’s Kesubah it is we add the surnames. He writes that one should write the word “L’Mishpachas” (meaning family) after the father’s name. Thus if the chosson’s name is Moshe Goldman and his father’s name is Chaim, the following should be written: “Moshe Ben Chaim L’Mishpachas Goldman.” If one wrote “Moshe Ben Chaim Goldman”, the Kesubah is still valid.
Harav Yosef Shalom Elyashiv zt”l (Koveitz Beis Hillel 38) agreed with the ruling of Harav Moshe Feinstein zt”l and he writes that that was his personal custom. Harav Shlomo Zalman Auerbach zt”l would write the surname in parenthesis or brackets (Shalmei Simcha page 269). Harav Ovadia Yosef zt”l would write the surname. But he would not write the word “L’Mishpachas.” He would just write the surname following the father’s name. (Yalkut Yosef Nisuin page 78)
4. If the surname was not written, the Kesubah is still valid.
5. If the chosson is a kohen we write: “Moshe Ben Chaim Hakohen L’Mishpachas Goldman.”
6. Some have the custom to only write the surname the first time that the chosson and kallah’s names are mentioned in the Kesubah. Every other time that the chosson and kallah’s names are mentioned, the surnames are omitted. (See Hanisuin K’Hilchosom 11:147)
7. Many, however, have the custom not to write the surname in the Kesubah (see Yismach Lev page 62). Harav Yisroel Belsky shlit”a writes that the common custom is not to write the surnames of the chosson, kallah and witnesses in the Kesubah. And that even Harav Moshe Feinstein zt”l, who endorsed the writing of surnames in his sefer Igros Moshe, practically did not write them, in order to adhere to the common custom. (Shulchan Halevi 27:14)
8. Those who do not have the custom of using surnames for the chosson and kallah will not do so for the witnesses. The question is according to those who do write the surname for the chosson and kallah, what is the procedure for the witnesses? Harav Moshe Feinstein zt”l, who was a proponent of adding surnames in the Kesubah, writes that the witnesses should also sign their surnames. However, it is reported that Harav Shlomo Zalman Aurbach zt”l, who would add the surnames of the chosson and kallah in parenthesis, maintained that one need not do so for the witnesses.
If you have a question, comment, or an idea for an article please email me at firstname.lastname@example.org.