Courtesy of Ohr Olam Mishnah Berurah
Question: What are the particulars of the custom of giving machatzis hashekel before Purim?
Discussion: This custom is a remembrance of the half-shekel that was donated to the Beis Hamikdash in Adar every year101 (see above, page 608). It is customarily given before Minchah on Ta’anis Esther.102
The basic custom is to give one coin of a denomination of “half” of the local currency. However, it has become customary to give three such coins, corresponding to the three mentions of the word shekel in the parashah of the shekalim in the Torah.103
The Poskim debate whether one became obligated in the essential half-shekel obligation – and hence subject to the resultant custom – from the age of 20, or 13. However, it is customary to give even on behalf of male children; and in fact even on behalf of a pregnant woman’s unborn baby.104
Women are exempt from giving machatzis hashekel.105 However, many do customarily give the machatzis hashekel on behalf of women as well.106
101 Rema 694:1.
102 Maharil, Hilchos Purim; Rema ibid. If one did not give machatzis hashekel then, one should give it on Purim morning before the Megillah reading. If one did not give it then either, one should give it at any time throughout Adar (Hilchos Chag Bechag, Chapter 5, note 1).
103 Rema ibid.
104 Mishnah Berurah 694, note 5.
105 Magen Avraham, 694, note 3; Mekor Chaim 694, note 1; Aruch Hashulchan 694:8.
106 Hilchos Chag Bechag 5:4, and note 9.