A. When to begin and end Neilah:
One is to begin Davening Neilah close to the beginning of sunset and end Neilah close to Tzeis Hakochavim. Nevertheless, the custom [in many communities] is to end Neilah past nightfall, and those who follow this custom are not to be protested. Those who follow this custom should beware to begin Neilah with much time left in the day.
B. Opening the Aron:
The Aron remains open throughout the entire Neilah prayer, until after the Tekiah in Kaddish.
C. Yom Kippur that falls on Shabbos-Mentioning Shabbos when Neilah extends past nightfall:
When Yom Kippur falls on Shabbos and Neilah extends past nightfall, Shabbos mentioned in Shemoneh Esrei, but not in the confession that is said after Neilah. [This follows the ruling of Admur in his Shulchan Aruch. However, in his Siddur he rules that Shabbos is never mentioned in the confession of any of the Tefilos, and confession is never said after Neilah.]
D. Nesias Kapayim-Birchas Kohanim in Neilah:
Nesias Kapayim is meant to be performed in the Neilah prayer, prior to nightfall. In the Ashkenazi provinces where the custom is to extend Neilah past nightfall, Nesias Kapayim is not performed. [Practically, according to the Chabad custom, Kohanim do not recite the priestly blessing during Neilah, even if the Chazan finishes Neilah prior to night.]
Should the Chazan recite Yevarechicha? The Chazan is to recite the priestly blessing of “Elokeinu”, as is usually said when there are no Kohanim available, even if the prayer extends past nightfall.
E. Avinu Malkeinu:
Avinu Malkeinu is recited after Neilah, even when Yom Kippur falls on Shabbos.
F. The conclusion of Neilah:
Shema: At the conclusion of Neilah, the congregation repeats the verse of “Shema” after the Chazan [with intense concentration, visualizing actually giving up one’s life for the sake of Heaven].
Baruch Sheim: The custom is to repeat “Baruch Sheim Kevod Malchuso Leolam Vaed” three times at the conclusion of Neilah, after reciting Shema Yisrael.
Hashem Hu Haelokim: Hashem Hu Haelokim is recited seven times, in order to escort the Divine presence which was with us throughout the prayer and is now being elevated above to Heaven.
Kaddish Shalem; Napoleon’s march; Blowing the Shofar: Kaddish is recited after the recitation of Hashem Hu Elokim. Prior to Tiskabel, the congregation sings Napoleon’s march. After the conclusion of the song, the Shofar is blown. See next Halacha!
The nine remaining Chapters of Tehillim: At the conclusion of Neilah, the remaining nine chapters of Tehillim are read.
G. Blowing the Shofar:
How many blows are to be blown? One is to blow one Tekiah after the singing of Napoleon’s march, prior to Tiskabel.
Must one wait until after night to blow the Shofar: It is permitted to blow the Shofar past sunset, during Bein Hashmashos. [Nonetheless, some calendars write to wait 20 minutes after sunset. Some claim that in Beis Chayeinu the Rebbe was accustomed to delay the blow until after Tzeis Hakochavim. According to all, one may blow after nightfall, before Havdala. Thus, it is permitted to blow more than one blow at this time, if need be.]
Must one stand throughout Neilah?
From the letter of the law, one is not required to stand when the ark is open, however, the custom of the world is to stand out of respect. Nevertheless, if it is difficult for one to stand, he may be seated.
Does one pray Tashlumin if he forgot to Daven Neilah?
This matter is disputed in Poskim.
Sparks of Chassidus
Neilah is the fifth and last prayer of the day. Each prayer corresponds to another level of a Jews G-dly soul. This prayer corresponds to the highest level of the soul, called the Yechidah. The Yechida is absolutely united with G-d Himself and is not affected by sin. This level is revealed during Neilah. One should say this prayer with much concentration, trying to internalize this most precious moment.
 Shulchan Aruch chapter 623
 Admur 623/2-4
Admur [ibid] records two opinions in this matter:
1st Opinion-Ramban [623/2]: Neliah is to extend until close to nightfall [Tzeis Hakochavim], being that it corresponds to the closing of the gates of the Heichal of the Beis Hamikdash, which was done by day [after the lighting of candles by noon].
2nd Opinion-Rif [623/3]: There is no limit regarding when it should be concluded, and thus it may be continued past nightfall. According to this opinion, the term Neilah represents the concluding prayer of the day, and not the closing of the gates of the Beis Hamikdash, and it is Davened in close proximity to the closing of the heavenly gates which are locked at the conclusion of prayer.
The final Ruling [623/4]: The main opinion is like the 1st opinion [to begin close to the beginning of Shekiah and end close to Tzeis Hakochavim], although the custom is like the second opinion [to end past nightfall], and those who follow it should not be protested. In any event, those who end late should start Neilah with much time left in the day.
 Sefer Haminhagim p. 125
 Admur 623/6
 Admur 623/8
Ruling of Admur in Shulchan Aruch ibid: Being that Birchas Kohanim is considered Avoda, it cannot be done at night, after Tzeis Hakochavim. Therefore, the Chazan must reach Birchas Kohanim prior to nightfall [Tzeis Hakochavim] and if necessary, he is to skip saying Selichos in order to be able to say it on time. Nevertheless, in these provinces where the custom is to extend Neilah past nightfall, they do not say Birchas Kohanim at all.
Michaber: The Beis Yosef writes to say Birchas Kohanim.
Rama: The Rama rules that the custom is not to say Birchas Kohanim, and the M”B explains that this custom applies even if it is still daytime.
Litvish Custom: The custom in Litvish communities today is to say Birchas Kohanim before Shekiah. [However, the M”B rules like Rama that it is not said even when still day.]
 Sefer Haminhagim p. 125; Rebbe in name of Freideker Rebbe as a clear directive, although one year, as a Horaas Sha it was said. [Igros Kodesh 18 p. 70] This follows the ruling of the Rama, as explained in M”B, and the custom mentioned by Admur that today it is never said.
In Luach Kolel Chabad it states that the custom is to say it when it is still day. However, as stated above, this is not the Chabad custom. Some explain that the above custom was only relevant to the Diaspora, however in Eretz Yisrael where Nesias Kapayim is done daily, the custom does not apply and hence Nesias Kapayim is to be done before sunset. Practically, however, this is not practiced by Anash even in Jerusalem. [See Pardes Chabad article of Rav Tuvia Bloy]
 The reason: Since the prayer began while still day, therefore we are not particular regarding this. [Admur ibid]
 Admur 623/9
 The reason: As now is the final signing of the decree and we require supplication for mercy, and if not now then when. [ibid]
 Admur 623/10
 Siddur in Machzor
 Admur 623/10; 61/12; Taz 61/4
 Admur 623/10; 61/10; Michaber 61/12; Tosafus Brachos 34a
 Admur 623/11
 Sefer Haminhagim p. 126
 Sefer Haminhagim p. 126
Ruling of Admur in Shulchan Aruch ibid: The blow is to be done after the entire Kaddish Shalem is recited.
 Admur ibid
Reason behind the blowing of the Shofar: The Shofar is blown to signify the elevation of the Shechina, as the Shechina departs with the sound of a Shofar. In addition, it is blown to empohasize to the public that Motzei Yom Kippur is a Yom Tov, and one is to increase in festivities on this night. [Admur ibid]
 Siddur Admur [no difference of Nussach is mentioned]; Gloss of Tzemach Tzedek [printed in Shaar Hakolel 4/9]; Piskeiy Hassidur 171; Sefer Haminhagim p. 118 [English]; Kaf Hachaim 582/39 based on Arizal [regarding all Aseres Yimei Teshuvah, however including Neilah] and so is the custom of the Sefaradim [Piskeiy Hassidur ibid]; Shaar Hakolel 4/9 based on Seder Hayom that explicitly says to not say it and Mishnes Chassidim and Siddur Yaakov Kopel that omits it.
The reason: The dialect of Kaddish contains exactly 28 words according to Kabala. Based on this one is not to change the dialect even during Aseres Yimei Teshuvah. [Kaf Hachaim ibid] However the M”E 582/1 writes that when Lieila is repeated the word Min Kol Birchasa is omitted and read as Mikol Birchasa, and hence there remain only 28 words.
Ruling of Admur in Shulchan Aruch: In Shulchan Aruch of Admur 582/16 he rules that one adds “Lieila Lieila” throughout all the Kaddeishim recited during Aseres Yimei Teshuvah.
Other Poskim: The following Poskim write one is to recite Leila Ulieila throughout Aseres Yimei Teshuvah: Levush 582/8; M”A 584/4; Admur ibid; M”B 582/16; M”E 581/1; Siddur Yaavetz; Kitzur SHU”A 129/1; Darkei Chaim Veshalom 706; Luach Eretz Yisrael. All the above Poskim write that one is to repeat “Lieila Lieila”. However in some Sefarim it says “Lieila Ulieila”. [Likkutei Mahrich; Piskeiy Teshuvos 582/9] The reason for repeating the word Leila is because during Aseres Yimei Teshuvah Hashem sits in judgment and His name is hence glorified before the masses much more than the regular year. Hence they emphasize that He is very exalted during this time. [Machatzis Hashekel 582/4 in name of Levush ibid] Some Poskim rule it is only to be repeated on Rosh Hashanah and Yom Kippur. [Elya Raba 582]
 Sefer Haminhagim p. 125 [English]; Hayom Yom 10th Tishrei; Kuntrus Hashulchan p. 63 based on Mamar of Rebbe Maharash [Toras Shmuel 1874 p. 284]; See Otzer Minhagei Chabad 262
Other opinions: The Shaar Hakolel 4/9 states that it is not to be repeated at all, even during Neilah, and that doing so has no source.
 Sefer Haminhagim p. 126
 Admur 623/11
 Sefer Haminhagim p. 126
 Reason behind the blowing of the Shofar: The Shofar is blown to signify the elevation of the Shechina, as the Shechina departs with the sound of a Shofar. In addition, it is blown to emphasize to the public that Motzei Yom Kippur is a Yom Tov, and one is to increase in festivities on this night. [Admur 623/12]
 First custom in 623/11 and so is the Chabad custom as recorded in Oatzer Minhagei Chabad p. 243 and Luach Kolel Chabad which was edited by the Rebbe.
Other customs brought by Admur in the Shulchan Aruch: Admur states: The custom is to blow one Tekiah [and so is the Chabad custom], although there are those who are accustomed to blow Tashrat [and so is the Litvisher custom. The Sefaradim blow Tashrat, Tashat, Tarat].
 Admur 623/11
 The reason: Being that it is not a Shevus Gamur [complete Rabbinical prohibition] and is rather only forbidden due to Uvdin Dechol [a mundane act]. [Admur ibid]
 See Otzer Minhagei Chabad p. 243
 Perhaps this was done in order to prevent a stumbling onto the unobservant public who may think that they may begin to eat already after the blow, even if it is still prior to nightfall.
 As some permit performing after Shabbos, prior to saying Havdala, all Rabbinical prohibitions which are forbidden simply due to them being a mundane act, and so is the custom to be lenient on Motzei Yom Kippur. [Admur 299/15]
 Taz 242/13; Siddur Yaavetz; P”M 141 M”Z 3; Beir Moshe 1/23; Custom of Rebbe in the early years. In the later years the Rebbe sat. [Otzer Minhagei Chabad 190]
Other opinions: See Panim Meiros 1/74 that one is to stand if he is able to see the Sefer Torah.
 Beir Moshe ibid as there is no requirement from the letter of the law to stand while the ark is open.
 See Piskeiy Teshuvos 623/1