I have lately been involved in helping a friend which had done a Giur at the age of 17 just before the army, under the supervision of the Rav Hachi of the Army of that period. following this giur, this friend did not observe Shabbat, Kashrut and Ishut. This person joined 10 years latter a Yeshiva, But was lately told that accordingly to the Halacha, the Giur was not "Kosher", and there was a need to do a "Giur Le Humra" What is a Giur Le Humra What is the identity of this person - Jewish/non-Jewish What is the identity of his Kiddushin (which he has done in the meantime) Anything else I should tell him?
Generally, giur l'chumra is applied when a previous conversion has a doubt, but is not without basis. It is impossible to know what the basis of the original giur was in this case. I would treat the friend as a Jew who is missing a requirement in order to finalize acceptance in the community. Certainly the kiddushin must be considered valid, though in some cases a second kiddushin (l'chumra) could be asked for.