Q&A from the Bais HaVaad Halacha Hotline

I Do Declare

October 1, 2025

Q Does Kol Nidrei have any practical application regarding nedarim?

A Kol Nidrei is a declaration canceling all nedarim, shvuos, and other binding verbal commitments. The reason Yom Kippur was chosen for this is that it is a time when people reflect on their past and regret their mistakes. Since the foundation of how a neder is permitted is through charatah (regret), this time is deemed appropriate (Shitah Mekubetzess, Nedarim 23b). Additionally, Yom Kippur is a time for spiritual purification, so we work to purify ourselves from possible nedarim transgressions (see Tur O.C. 619). Further, Yom Kippur does not atone for a person who withholds a neder pledge to tzedakah, so in case such a pledge was forgotten, hataras nedarim is performed (Shibalei Haleket 317).

The minhag of Kol Nidrei dates back to the times of the Geonim (Tur), and the idea is subtly alluded to in the Gemara (Nedarim 23b). Some attribute the institution of Kol Nidrei to the Anshei Knessess Hagedolah, who standardized the text of our tefilah (see Shitah Mekubetzess ibid).

Rabeinu Tam (cited by Tosfos, Nedarim ibid.) challenged the established text representing Kol Nidrei as a standard hataras nedarim, arguing that hataras nedarim requires three men rather than a lone chazan, the neder must be specified, and the petitioner must provide a valid basis for regretting the neder. Therefore, Rabeinu Tam changed Kol Nidrei to the future tense, restructuring it as a declaration that future nedarim are null and void. This resembles the declaration made on Erev Rosh Hashanah (the mesiras moda’ah). The halacha follows Rabeinu Tam, and the text includes a clause that the nullification is intended to affect the nedarim of the coming year. For this reason, each person must say the words. In contrast, according to the original hataras nedarim text, there is no need for anyone other than the chazan to say it.

Nevertheless, many maintain that the original text should also be included, as there are justifications for it, so some include the nullification of last year’s nedarim as well.

The declaration canceling future nedarim is only effective if one forgets about it when making a neder. If he remembers it and makes the neder anyway, the neder overrides the declaration (Mishnah Brurah ibid. 2). There are additional limitations, so the Kol Nidrei nullification should not be relied upon without consulting a rav.