Different customs in writing Sefer Torah, Tefillin and Mezuzah

Hi,

One may use a sefer torah, mezuzah or set of tefillin which was written in accordance with a custom that is not the norm in a particular community. This is not ideal, but since the differences are known only to scribes, this would not be considered a violation of communal custom.

Certainly, we do not rule a particular custom to be 'invalid', where it is one of the traditional types of script.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 5:2)

Have a great day,
Mordechai

Questionable tefillin and mezuzot

Hi,

One who has tefillin or mezuzot of uncertain validity should have them checked immediately, or put them in genizah [storage] where they will not be used by accident. One should not keep them in a place where someone might unwittingly use them.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 4:12)

Have a great day,
Mordechai