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

Tefillin script

Hi,

One who davens with nusach Ashkenaz may wear tefillin written according to the rules of the Ari (even though the Ari's followers daven with nusach Sfard). This is not considered inconsistent conduct.

(Rav Moshe Feinstein, Igrot Moshe Orach Chaim 2:24)

Have a great day,
Mordechai