Zecher LeMachatzit HaShekel
When should it be given?
- Some have the minhag to give it before Mincha of Taanit Ester, while some have the minhag to give it after Mincha but before reading of the Megillah.
Calling it Zecher LeMachatzit HaShekel
- One should make sure to call the coins one is giving Zecher LeMachsit HaShekel and not Machsit HaShekel so people don't think it is hekdesh. 
How much should one give?
- The Ashkenazic minhag is to give three coins which are half the value of the common coin in that time and place. In America, the minhag is to give three half dollars, yet some say it's preferable to give coins which have 9 grams of silver (like Sephardim).
- Some poskim hold that it is necessary to give coins that contain actual silver, like silver dollars minted before 1964. However, most poskim disagree and that is the minhag.
- In Israel, some say that one can use half dollars since it is accepted as cash and others argue that it shouldn’t be used because it’s not commonly used in Israel. Rather some say that one should use 3 half shekels.
- According to Sephardim, one should give an amount worth 9 grams of pure silver. It's preferable to give it in the form of 3 coins, and if 3 coins are less than 9 grams one should supplement that amount up to the value of 9 grams.  If one is poor one may give a half of a modern shekel (for someone who lives in Israel). The Moroccan minhag is to give half of the common currency like Ashkenazim. The minhag is not to take the coins from the tzedaka collection pan in your hand, just to donate the money.
- Some donate a dollar and a half in cash, then pick up three coins that are customarily found in the shul, and then call those coins the zecher lmachasit hashekel. Some say that it isn't necessary to do that and it is sufficient to donate the dollar and a half and not pick up the half dollar coins.
Who is obligated to give it?
- Some say one should give a Zecher LeMachsit HaShekel for anyone above Bar or Bat Mitzvah, but some say that one only needs to give for those above the age of 20.  It’s preferable to follow the first opinion. 
- Some say that women are obligated in this mitzvah  and some exempt them. Nonetheless, everyone agrees that it is preferable for women to give Zecher LeMachsit HaShekel. 
- It’s preferable to give for one’s small children. 
To whom is the money given
- Some say that the money should be given to poor people , some say it should be given to the upkeep of the Shul , and some say that it should be given to Yeshivas or establishments of Torah. 
Can one use maaser money for it?
- Someone who takes separates a tenth of one’s income for Tzedaka (Maaser) shouldn’t use that money for Zecher LeMachsit HaShekel nor for Matanot LeEvyonim. 
- Maasechet Sofrim 21:3 writes that one should give the Machsit HaShekel before parshat zachor. Sh”t HaGeonim (Geonei Mizrach Umaarav 40) writes that those who have the minhag to collect Shekalim are doing improperly because those coins become hekdesh but one may collect tzedaka. Rama 694:1 writes that the minhag is to give Zecher LeMachsit HaShekel before Purim.
- Rama 694:1 writes that the minhag is to give the Zecher Machsit HaShekel before Mincha of Tanit Ester. Mishna Brurah 694:4 affirms this minhag. Kaf HaChaim 694:25 adds that it should be given on Tanit Ester even if the Tanit is pushed off to the previous Thursday in order to combine the tzedaka with the fast.
- However, Chazon Ovadyah (Purim pg 101) and Piskei Teshuvot 694:3 write that the minhag is to give it before the reading of the Megillah based on Gemara Megillah that says our shekalim counteract the shekalim of Haman read about in the Megillah. Kitzur Shulchan Aruch 141:5 seems to agree.
- Natai Gavreil (purim 26:1) in name of Siddur Yavetz and Luach Eretz Yisrael write that the minhag is to give it between Mincha and maariv. Piskei Teshuvot (pg 119) writes that the minhag of Rav Shlomo Zalman and Rav Elyashiv was to give at the night of the 15th before the megillah. Yalkut Yosef (Kitzur Shulchan Aruch Zecher LeMachsit HaShekel #1) writes that if one didn’t give it before Purim one should give it before the reading of the Megillah.
- Maasechet Sofrim 21:3 writes that one shouldn't say one is giving the Machsit HaShekel for atonement but only as a voluntary. Darkei Moshe 694:1 quotes this from the Aggudah. Therefore, Rav Ovadyah in Chazon Ovadyah (Purim pg 101) writes that one shouldn't call it Machsit HaShekel but rather Zecher LeMachsit HaShekel so that people don't think one is making it hekdesh. Rav Schachter (www.yutorah.org “Purim” 7/9/2008, min 1-3) also explained the Darkei Moshe in this way. Torat HaMoadim (pg 96), Zichronot Eliyahu (Shin #2), and Shalmei Todah (purim pg 270) agree. This is in opposition to Sh”t Divrei Yosef 52 who says that even saying that it is Zecher LeMachsit HaShekel is an issue and against Sh”t Zecher Simcha 76 who writes that it's permitted even to call it Machsit HaShekel.
- The Rama 694:1 writes that one should give three coins corresponding to the three times Trumah is mentioned in the parsha. These coins should be half of the regular coin of the time and place. Almost all Ashkenazic achronim including Kitzur S”A 141:5, Aruch HaShulchan 694:8, Beiur Halacha s.v. VeYesh Litan, and Nitei Gavriel 26:3 accept the Rama as halacha. Piskei Teshuvot 694:4 writes that one should be strict for the Kaf HaChaim. (See also Orchot Rabbenu of the Steipler vol 3 pg 51-52, Teshuvot VeHanhagot 5:233, and Halichot VeHanhagot pg 22 quoting Rav Elyashiv). However, Sh”t Tzitz Eliezer 13:72 argues that giving the value of the Machsit HaShekel in silver is certainly not the intention of the Rama, it's expensive when paying for all family members, and it may cause people to think the money is hekdesh; rather one should give half of the common coin even if it's less than the value of 9 grams of silver. It seems that the minhag is to give 3 half dollars because the dollar in a common currency in America (www.aish.com, www.torah.org). Nitai Gavriel (ch. 26 fnt. 8) quotes the Divrei Tzvi and Minchat Elazar who hold that one should give three halves of the smallest currency because it is just a zecher.
- Piskei Teshuvot 694:4 and Rav Elyashiv quoted by Halichot VeHanhagot (pg 22) say that it’s preferable to give both 3 half shekels and 3 half dollars (the old ones made from silver).
- Halichot Shlomo (Moadim vol 2, 18:9) records Rav Shlomo Zalman's minhag to use 3 half dollars because they contained actual silver. The footnote points out that this is only true of silver half dollars minted before 1964. Kuntres Piskei Halachot p. 48 writes that there are some who are careful to use coins which have actual silver in them and quotes that this was the minhag of the Chatom Sofer. Piskei Teshuvot 694:4 quotes the minhag for the gabbay to arrange for there to be three real silver dollar coins (minted before 1964) and then everyone buys them one at a time for $1.50 or three half shekels and donates them back for zecher lmachasit hashekel.
- Steipler (Orchot Rabbenu v. 3 p. 163, new edition) also used half dollars for machasit hashekel even at the end of his life (1985). It isn't clear if he used silver half dollars with actual silver at the end of his life.
- Rav Moshe Feinstein (Shemaytata Dmoshe 694:8), Rav Shmuel Kamenetsky (Kovetz Halachot Purim 3:4 fnt 5), and Teshuvot Vehanhagot 4:172 all hold that it isn't necessary for the coins to have actual silver content and the common half dollars today are acceptable for zecher lmachsit hashekel. Aish.com, Chabad.org, Rabbi Yair Hoffman concur that one should give three of the common half dollars (and not specifically the ones minted before 1964). Rav Shternbuch in Teshuvot Vehanhagot writes that it is very questionable if one can even use real half dollars because they're no longer accepted as currency.
- Rav Shlomo Zalman in Halichot Shlomo (Moadim vol 2, 18:9)
- Rav Chaim Kanievsky in s.v. Mi) quoted in Piskei Shemuot (pg 116). Igeret Hapurim (ch. 2 fnt. 19) quotes Rav Chaim Kaneivsky (Derech Emuna Maaser Sheni Biurim 4:14 s.v. mi) as holding that using half dollars in Israel doesn't work, but he also quotes Rav Elyashiv that it does.
- Rav Elyashiv quoted in Piskei Shemuot (pg 117) in name of the Sefer BaLaylah HaHu and in Yeme Mishteh VeSimcha (pg 19 note 16). Rav Elyashiv quoted in Piskei Shemuot (pg 117) says that one shouldn't give one and half shekelim but specifically 3 half shekels.
- Kaf HaChaim 694:20 writes that the Machsit HaShekel should be evaluated according to the value of a Machsit HaShekel in the days of the Bet HaMikdash and concludes that it is 3 Durhams of silver. Rav Ovadyah in Yalkut Yosef (Zecher LeMachsit HaShekel #2-3) and Chazon Ovadyah (Purim, pg 102) rules that one should give the value of 3 Durhams which is 9 grams of pure silver. A gram of silver currently is about $1.10 and 9 grams is about $10. [Even though Rav Mordechai Eliyahu in Maamer Mordechai (Moadim 63:1), Ish Matzliach 694:4-5, and Rav Ovadyah in Sh”t Yechave Daat 1:86 write that one should give the value of 10 grams, this is only according to the old measurement of the Durham (See Yalkut Yosef Sovah Semachot pg 278).]
- The Kaf HaChaim 694:23 writes that from Rashi's explanation of Chumash only one of the Trumot in the pasuk refer to the Machsit HaShekel. Thus, Gra in Maaseh Rav 233 and Rav Mordechai Eliyahu in Maamer Mordechai (Moadim 63:2) write that there is no reason to give three coins and one coin suffices. However, Chazon Ovadyah (pg 103) writes besides giving the value of 9 grams of silver, it's proper to give 3 coins in accordance of the Rama. Rabbi Mansour (Daily Halacha 3/15/2011) writes that one should give three half dollars, preferably those minted before 1964, and if those coins are less than the value of 9 grams of silver then one should supplement it so that one gives the value of 9 grams of silver.
- Yalkut Yosef (Kitzur S”A Zecher LeMachsit HaShekel #4)
- Magen Avot (R' Lebhar v. 1 p. 429)
- Rav Schachter (Corona teshuva #56)
- Rama 694:1 based on the Rav Ovadyah MeBartenura holds that one is only obligated from the age of 20. However, the Tosfot Yom Tov (Shekel perek 1) quotes many others who hold that one should give it from the age of Bar or Bat Mitzvah. This dispute is quoted in Mishna Brurah 694:5.
- Yalkut Yosef (Kitzur S”A Zecher LeMachsit HaShekel #5)
- Yalkut Yosef (Kitzur S”A Zecher LeMachsit HaShekel #6)
- Sh”t Shevet HaLevi 7:183 writes that it’s preferable to give for women. Piskei Teshuvot 694:5 and Halichot Shlomo (chapter 18 note 3) write that the minhag is that women are also obligated. Lastly, Rav Nassim Karlitz (quoted in Piskei Shemuot pg 119) holds that women are exempt but some hold that they’re obligated.
- Mishna Brurah 694:5 in name of the Eliyah Rabba, Yalkut Yosef (Kitzur S”A Zecher LeMachsit HaShekel #6)
- Levush 694:1, Shaarei Teshuva 694:2, see Sh"t Yechave Daat 1:86
- Kaf HaChaim 694:22
- Yalkut Yosef (Kitzur S”A Zecher LeMachsit HaShekel #7)
- Yalkut Yosef (Kitzur S”A Zecher LeMachsit HaShekel #8), Sh”t Yechave Daat 1:87