- It is forbidden to lay tefillin on Shabbos and on Yom Tov. (ShA1)
- If you have no choice, you may move the tefillin on Shabbos and on Yom Tov in order to protect them. Otherwise, consider them kaylim shemelachton l’issur. (MB2)
- Also on Chol Hamoed it is forbidden to lay tefillin. (ShA2)
- Some say that Chol Hamoed is obligated in tefillin just don’t say the berachos on them out aloud like you usually do. Take them off before Hallel. (Rama2 – MB7)
- Those who remove their tefillin after Kedusha must still be careful to listen to the repetition of the chazzan. (MB7)
- It is best not to say a beracha on the tefillin of Chol Hamoed. Also make a condition: “If I am obligated, I am wearing them for the mitzva, and if I am not, I am not wearing them for the sake of the mitzva.” (MB8)
- It is improper to have, in one shul, some wearing tefillin and others not. (MB8)
