Rosh Hashana is the Jewish New Year which is both a holiday as well as a day of Judgement. Following Rosh Hashana until Yom Kippur, there is a period called Aseret Yemei Teshuva, the Ten Days of Repentance. The laws and customs for Rosh Hashana and Aseret Yemei Teshuva are outlined below:
- 1 Customs of Erev Rosh Hashana
- 2 Candle lighting
- 3 Shofar
- 4 Second Day of Rosh Hashana
- 5 Simanim
- 6 Sleeping on Rosh Hashana
- 7 Minhag of Tashlich
- 8 Fasting on Rosh Hashana
- 9 Prayers of Rosh Hashanah
- 10 Yaaleh Veyavo
- 11 Links
- 12 Sources
Customs of Erev Rosh Hashana
- Tachanun is not recited on Erev Rosh Hashana for Shacharit or Mincha, even though during selichot which are said by night or at least before Netz Hachama we do recite the yud gimmel middot and the nefilat apayim.
- On the day before Erev Rosh Hashana, tachanun is recited at mincha. 
- We do not blow the shofar on erev rosh hashana and if one needs to practice blowing for the holiday, he should do so in a private room. 
- There are five main customs observed on Erev Rosh Hashana: 1) Laundering one's clothing. 2) Cutting one's hair. 3) Dipping in the mikveh. 4) Visiting the cemetery. 5) Giving tzedaka. 
- Some have the custom of receiving lashes on Erev Rosh Hashana, while others do so on Erev Yom Kippur.
Visiting the Cemetery
Fasting on Erev Rosh Hashana
- There is a custom to fast on Erev Rosh Hashana. 
- Some say that the minhag is that women do not fast on Erev Rosh Hashana. 
- One who is still fasting at mincha, should recite aneinu during mincha,  For the chazzan, if he doesn't plan on finishing the fast, he shouldn't recite aneinu in the chazarat hashatz at all. 
- One doesn't need to have to accept this fast upon himself during mincha the day before. 
- According to Ashkenazim, it is possible for someone to accept upon themselves to fast on Erev Rosh Hashana for a partial fast and then break their fast after plag mincha or if they are weak after Mincha Gedola. He can Anenu in Mincha if he is still fasting.
Dipping in the Mikveh
- The custom is to dip in a mikveh on erev rosh hashana in honor of rosh hashana, however this isn't required according to the law and therefore a beracha isn't recited and the laws aren't as strict.  If one cannot make it to a mikveh, he should try to spill 9 kav (approximately 12 liters) of water even if in the shower. 
- A woman within her seven clean days from niddah shouldn't go to the mikveh on erev Rosh Hashana or erev yom kippur. 
- The beracha on candle lighting for Rosh Hashana is lihadlik ner shol yom tov, without mention of Yom Hazikaron. 
- It is a mitzvah from the Torah to hear the Shofar blows on Rosh Hashana. 
- The proper beracha is lishmoa kol shofar. However, if one recited litkoa shofar or al tekiat shofar, he fulfills his obligation. 
- The sephardic custom is that on the first day of Rosh Hashana, the beracha of shehecheyanu is recited after lishmoa kol shofar.  If the first day is Shabbat and therefore we do not blow the shofar, shehecheyanu is recited on the second day after lishmoa kol shofar.  If a sephardic person is blowing shofar for an ashkenaz congregation on the 2nd day of Rosh Hashana, then one of the ashkenaz congregants should recite the shehecheyanu. If the sephardic shofar blower, recites shehecheyanu anyway, the congregation has nevertheless fulfilled their obligation of reciting it. 
- The congregation should stand while the Baal Tokeah makes the Brachot on the shofar and then they may sit for the blows prior to Mussaf. For the blows during Mussaf and the Chazarat HaShatz, the congregation should stand.
- One who couldn't go hear the shofar with a congregation and is having it blown for him at home, must stand for the shofar blowing. 
- The custom is to stand even for the tekiot which are referred to as the tekiot dimiyushav, the 1st 30 tekiot, 3 sets of Tashrat, Tashat and Tarat.  A weak, ill, or old person can be lenient. 
- The 30 tekiot after that are referred to as the tekiot dimeumad because one is required to stand for those. However, if one sat during these tekiot he has nevertheless fulfilled his obligation. 
- One should refrain from talking from when the beracha is recited until after all 100 tekiot are blown.  One should also try not to cough or yawn during the shofar blowing so as not to confuse any listeners. 
- If one is unsure if he heard the shofar or not, he should hear it again without a beracha. 
- Ideally, the shofar blower should try to blow it from the right side of his mouth, but this certainly doesn't prevent one from fulfilling his obligation if he doesn't. 
Second Day of Rosh Hashana
- In Kiddush of the second day of Rosh Hashana one should recite Shehechiyanu. Since it is a dispute whether we should include Shechiyanu it is proper to have a new fruit or wear a new garment and have that in mind while saying Shehechiyanu.
- Some poskim hold that the new fruit should be tasted after kiddush before the Netilat Yadayim and Hamotzei. However, others say one can wait until the meal.
- There is a minhag of dipping the challah in honey on Rosh Hashana. Some only dip the challah in honey, while others dip the challah in salt as well as honey. 
- There is a minhag to eat certain fruits and vegetables as a good omen for the coming year on both nights of Rosh Hashana. Some have this minhag only the first night. 
- If one is eating dates and other fruits, one should make a HaEitz on the dates because they’re from the seven species with which Eretz Yisrael is praised. Some say that one doesn’t make a HaAdama on vegetables during the meal. 
- Some say that one should say the Bracha of HaEitz, eat a little of the fruit, then make the Yehi Ratzon before continuing to eat, while others hold that one should say the Yehi Ratzon prior to the Bracha. 
- One may say the Yehi Ratzon’s with Hashem’s name.
- These fruits and vegetables include: dates, pomegrantes, beets, gourd, black eyed peas, fish head, and apple. 
- One should eat these fruits and vegetables in the meal after having eaten a Kezayit of bread. 
Sleeping on Rosh Hashana
- It's a proper minhag not to sleep on Rosh Hashana. Someone who has a headache should sleep a little after midday in order to perform the mitzvot and prayers better. 
- After the meal a person should go to the shul to learn according to his ability. Some have the practice of reading Tehillim twice over Rosh Hashana. A person who usually studies halachot should learn halachot rather than say Tehillim. In any event, one shouldn't waste time on this holy day of Rosh Hashana and wasting one's time on Rosh Hashana is like sleeping.
- Some poskim advise that it isn't appropriate to have tashmish on Rosh Hashana unless it is her Tevilah night.
Minhag of Tashlich
Where and When?
- The minhag is to say Tashlich near an ocean or river on the first day of Rosh Hashana.  The minhag is to say it after mincha 
- It is preferable for there to be living fish in the body of water. 
- If one didn't get a chance to do it on the first day, one should still do it on the second day after mussaf, while others say to do it after Mincha.
- The custom is to recite certain pesukim that are printed in the machzorim. 
- Many have the custom of shaking out their pockets as a symbol of throwing at one's sins. 
- Many poskim suggest that men and women should avoid being there at the same time so that it doesn't become an inappropriate, mixed social scene on our day of Judgment. 
- When the first day of rosh hashana falls out on Shabbat, some poskim say to postpone it, while others say just to say tashlich then. 
Fasting on Rosh Hashana
- It's forbidden to fast on Rosh Hashana.  Nonetheless, it's permissible to allow prayers to extend past chatzot (halachic midday) and fast until the afternoon. 
- There is a mitzvah of Kavod and Oneg on Rosh Hashana since it is called "mikreh kodesh".
Prayers of Rosh Hashanah
- If one forgot to switch from Atta Kadosh to HaMelech HaKadosh the first night of Rosh Hashana one doesn't have to repeat Shmoneh Esrei as long as one said the Yom Tov Shmoneh Esrei, however, if one said the weekday Shmoneh Esrei or on the day of Rosh Hashana or the second night of Rosh Hashana one should repeat Shmoneh Esrei.  Some disagree and hold that one needs to repeat Shemona Esrei.
- Some poskim encourage crying during the prayers of Rosh Hashana while some forbid it. 
- If there's a Brit Milah in Shul on Rosh Hashana, the Milah should be preformed between Kriyat HaTorah and the blowing of the Shofar.
- If one forgot Yaaleh VeYavo in Benching on Rosh Hashana during the day one does not have to repeat benching, but during the nighttime one must repeat benching. 
Changes in Shemona Esreh
- During the Aseret Yemei Teshuva, the conclusion of the Bracha HaEl HaKadosh is switched to HaMelech HaKadosh.  If one forgot to say HaMelech HaKadosh and remembered within Toch Kedi Dibbur (2-3 seconds), then one should say HaMelech HaKadosh right then.  If one remembered only afterwards one must start from the beginning of Shmoneh Esrei. If one is unsure, it is assumed that one forgot. 
- The conclusion of the Bracha Melech Ohev Tzedaka UMishpat is changed to HaMelech HaMishpat. According to Ashkenazim, if one forgot, one doesn’t go back to the beginning of Shemona Esreh.  According to Sephardim, if one forgot and remembered within Toch Kedi Dibbur (2-3 seconds) then one should say HaMelech HaKadosh right then. If one remembered afterwards, some say that one should return to the Bracha of Hashiva, however, if one finished Shmoneh Esrei one must start from the beginning of Shmoneh Esrei. If one is unsure, it’s the same as if one forgot. However, some say that if one remembered after Toch Kedi Dibbur one need not repeat anything. 
- Three other additions to Shmoneh Esrei are the lines of Zachrenu LeChaim, Mi Kamocha, Ketov BeSefer Chaim, and UveSefer Chaim. One may not skip UveSefer Chaim in order to catch Kedusha with the congregation. 
- On Friday night, the words HaEl HaKadosh are changed to HaMelech HaKadosh in the Bracha Mein Sheva that the Sheliach Tzibbur says. If he forgets and remembers before the end of the Bracha he goes back to HaEl HaKadosh, if he remembers after concluding the Bracha, he doesn't repeat it. 
Changes in Kaddish
- The Ashkenazic minhag during the ten days between Rosh Hashana and Yom Kippur (Aseret Yemei Teshuva) is to say LeElah UleElah MeKol Birchata (in Kaddish) instead of LeElah Min Kol Birchata. 
Other Practices during Prayers
- Some have the minhag to stand bent slightly (hunched over slightly) during the Tefillot of Rosh HaShana and if one does so, one should make sure to stand straight for the end and beginning of each Bracha.  Some say it’s preferable to stand straight for the Tefillot. 
- Some have the minhag to daven slightly out loud during Tefillot of Rosh Hashana.  However, many authorities discourage this practice. 
- Chazon Ovadia (Yamim Noraim page 46), Shulchan Aruch 581:3, Kaf Hachayim 581:73
- Yalkut Yosef (Moadim page 21), Kaf Hachayim 581:74
- Yalkut Yosef Moadim page 21
- Shulchan Aruch OC 581:4
- Kaf HaChaim 581:58
- Shulchan Aruch 581:4. Kitzur Shulchan Aruch 128:13 points out that we are obviously not praying to the dead person themselves as that would be avoda zara, but rather that Hashem perform kindness and listen to our prayers thanks to the merit of these great tzaddikim. Mishna Brurah 581:27 as well as the Sefer Ikarim 4:35 write likewise.
- The Shulchan Aruch 581:2 writes that the custom is to fast on Erev Rosh Hashana. The Rama 581:2. writes that there is no need to finish the fast. Rabbi Eli Mansour says that one shouldn't eat until Kiddush that night. see Yalkut Yosef Moadim pg. 20, Halichot Olam 2:pg. 233
- Mishna Brurah 581:16 writes that women also fast, but Rabbi Yissachar Dov Krakowski says this isn't the custom.
- Mishna Brurah 562:7 says this is true even if you do not plan on finishing the fast. For sephardim, the Kaf Hachayim 562:8 says if you do not plan on finishing the fast to recite aneinu during elokay nitzor.
- Beiur Halachah 562:1 "aval."
- Mishna Brurah 581:16, Rabbi Yissachar Dov Krakowski. This is also the ruling of Rabbi Eli Mansour However, Revach.net quotes Rav Elyashiv as saying that if you don't fast every year, you should accept it during mincha the day before.
- Rama 581:2 writes that one doesn't need to complete the fast of Aseret Yemey Teshuva. Magen Avraham 581:10 and Mishna Brurah 581:16 apply this to Erev Rosh Hashana as well. Mishna Brurah 562:10 writes that for someone weak they can break their fast of hours at mincha gedola, otherwise they should wait until plag mincha.
- Halichot Olam 2: page 225, Moed Likol Chai 12:11. see also Rama 581:4.
- Yalkut Yosef Moadim page 22, Chazon Ovadia (Yamim Noraim page 51, 57).
- Chazon Ovadia Yamim Noraim page 59
- Kaf Hachayim 581:12, Yalkut Yosef Moadim page 22, Yabia Omer OC 2:30, Chazon Ovadia Yamim Noraim page 42
- Chazon Ovadia Yamim Noraim pg. 62. see there where he writes that it wouldn't be a problem of a hefsek between the beracha and the candle lighting to mention yom hazikaron, but lechatchila one shouldn't do say it.
- Yalkut Yosef 583:1 (Moadim pg. 36) from the pasuk in Bamidbar 29:1 יוֹם תְּרוּעָה, יִהְיֶה לָכֶם
- Yalkut Yosef Moadim pg. 36
- Yalkut Yosef Moadim pg. 36, Chazon Ovadia Yamim Noraim pg. 116
- Yalkut Yosef Moadim pg. 36,48, Chazon Ovadia Yamim Noriam pg. 112, 116
- Yalkut Yosef pg. 36, Sh"t Yabia Omer 1:29:11
- Yalkut Yosef 583:3 (Moadim pg. 36)
- Sh"t Haridbaz 4:25
- Mishna Brurah 585:2
- Shaar Hatziyun 585:2.
- Mishna Brurah 592:2
- Chayei Adam 141:9. Sh"t Minchat Yitzchak 3:44 and 4:47 says that Asher Yatzar may be recited during this time.
- Yalkut Yosef Moadim pg. 40
- Yalkut Yosef Moadim pg. 37, Chazon Ovadia Yamim Noraim pg. 161
- Yalkut Yosef Moadim pg. 41
- Shulchan Aruch OC 600:2
- Machasit Hashekel 600:22
- Rav Elyashiv (cited by Ashrei Haish 3:14:4 and Dirshu)
- Magen Avraham 583:1, Mishna Brurah 583:3, Kitzur Shulchan Aruch 129:9
- Nitei Gavriel (Rosh Hashana p. 209, n. 17) writes that the Chazon Ish and Stiepler's practice was to eat challah without salt on Rosh Hashana. See there for other sources on this matter.
- Kaf HaChaim 583:4. See Nitei Gavriel (Rosh Hashana p. 209) for different minhagim about whether to dip the challah in salt on the same side as it is dipped in honey or on the other side. See there also for a difference in minhagim whether to dip the challah in salt before dipping it in honey or afterwards.
- The Gemara (Horiyot 12a) says that a person should see gourds, fenugreek, leek, beets, and dates (though these definitions are the subject of controversy) on Rosh Hashana as a good omen. The Gemara (Keritut 6a) records the same statement with the text that a person should eat these fruits and vegetables as a good omen. Beit Yosef 583:1 notes the different versions and rules in S”A 583:1 that a person should eat these foods as a good omen. Kaf HaChaim 583:6 writes that if one can’t eat a certain food, he may just look at it and say the Yehi Ratzon nonetheless. Nitei Gavriel 29:24 agrees.
- Eliyah Rabba 583:1 writes that the minhag is to eat simanim on both nights of Rosh Hashana. Machazik Bracha 583:2, Chazon Ovadyah (p. 93), Teshuvot VeHanhagot 2:266 Yalkut Yosef Moadim pg. 29, Halichot Olam 2:[g. 227 and Rivevot Efraim 6:308:1 agree. However, Bnei Yisaschar 2:11 and Eishel Avraham MeButchach 583 explain the minhag of eating the simanim only on the first night of Rosh Hashana.
- Chazon Ovadyah (p. 98) writes that one shouldn’t make a Bracha upon the cooked vegetables because they’re considered as part of the meal. Halichot Shlomo (1:18), however, writes that one should make a HaAdama upon the gourd and exempt the other vegetables. To avoid all doubt, Nitei Gavriel 29:18 writes that one should make a HaAdama on a banana. Chut Shani (Rosh Hashana p. 48) agrees. It is noteworthy to mention that S”A 211:2 rules that when eating a food which is HaEitz and a food which is HaAdama one should make the bracha on the food which one prefers first.
- Halichot Shlomo (1:17) writes that one should make the HaEitz upon the dates because they’re from the seven species with which Eretz Yisrael was praised and they come before pomegranates on that list (see S”A 211:4). Ben Ish Chai (Nitzavim #4) and Nitei Gavriel 29:4 agree. Kaf HaChaim 583:13 records the practice of some people to make a HaEitz on the apple to exempt the dates. He explains that perhaps they brought out the apple first, and in such a case, one need not wait for the dates to come out to make the bracha upon them. Rivevot Efraim 8:558:3 writes that after making HaEitz on the dates, one may eat the apples prior to the pomegranates because the rules of precedence apply only regarding the Bracha, not regarding when each food should be eaten.
- Magen Avraham 583:2 quotes the Magalei Tzedek as saying that one should say the Yehi Ratzon in between the Bracha and eating. He explains that the Yehi Ratzon is a prerequisite for eating and thus does not constitute an interruption. The Magen Avraham, however, argues that it’s not such a requirement to say the Yehi Ratzon, and as such it is preferable to say the Yehi Ratzon after taking a bite. Mishna Brurah 583:4 and Chazon Ovadyah (p. 93) agree with the Magen Avraham.
- Rav Hershel Schachter (quoted in Halachipedia Article 5773 #3) said that it makes sense to say the Yehi Ratzon before the Bracha so that the Yehi Ratzon can function as a Tefilla and the eating as an action enhancing the Tefilla. Teshuvot VeHanhagot 2:266 agrees. See Chazon Ovadyah (pg. 93) who quotes the Chemdat Yamim who argues that one shouldn’t say the Yehi Ratzon prior to the Bracha because that is a violation of asking for one’s personal needs before praising Hashem (See Gemara Brachot 32a).
- Mishna Brurah 583:2 writes that the text of the Yehi Ratzon begin with Yehi Ratzon Milfanecha Hashem Elokeinu VeiyLokei Avoteinu with Hashem’s actual name. Teshuvot VeHanhagot 2:266 and Chazon Ovadyah (p. 93) agree. Nitei Gavriel 29:22, however, writes that from some poskim it seems that there was a text without Hashem’s name. Rav Shlomo Zalman’s minhag (Halichot Shlomo p. 12 note 70) was to say the first Yehi Ratzon with Hashem’s name and the others with Avinu SheBaShamayim. He explained that he did so because it’s difficult to have the proper kavana when saying Hashem’s name. Similarly, the Stiepler’s minhag (Orchot Rabbenu vol 2, p. 175) was to say them without Hashem’s name.
- Torat HaMoadim 4:1
- Chazon Ovadyah (yamim Noraim p. 93)
- Chazon Ovadyah (Yamim Noraim, pg 183-4), Kaf HaChaim 584:38,39, Ben Ish Chai Parashat Nitzavim:11, Yalkut Yosef Moadim page 33
- Yalkut Yosef (Moadim p. 33), Sh"t Yechave Daat 3:44
- Knesset Hegedola 581:8, Machzik Bracha 581:4, Birkei Yosef 581:18, Pri Chadash 581:4
- Chazon Ovadyah (Yamim Noraim, pg 186), Yalkut Yosef Moadim page 44. The name of this ritual comes from a verse in Michah 7:19 which says וְתַשְׁלִיךְ בִּמְצֻלוֹת יָם, כָּל חַטֹּאותָם. This minhag is mentioned by the Rama 583:2. Mishna Brurah 583:8 says that this is in remembrance of the akedat yitzchak, because the midrash says that on his way, Avraham had to cross a river, and when the water level was up to his neck he called out to Hashem and Hashem saved him. Rama in Torat HaOlah 3:56 explains that when one goes to an ocean or rivers and sees the greatness of Hashem's creations, he will immediately regret his sins and will be forgiven. The Kaf Hachayim 583:30 calls this an Ashkenazic minhag but adds that the custom in his times in Jerusalem was to say it. Maaseh Rav 209 writes that the minhag of the gra and his student Rav Chaim Volozhin was not to do tashlich at all, but Rav Moshe Harari in Mikraei Kodesh Rosh Hashana 14:note 4) writes that many people who generally follow the customs of the Gra do not follow him for this.
- Chazon Ovadia Yamim Noraim page 186. Rav Moshe Shternbuch in Teshuvot Vihanhagot 1:346 agrees but says that mincha should be said earlier in the day so tashlich could be said immediately afterwards because he doesn't think it is so simple that it's permissible to carry the siddur. Also see Moadim U'Zmanim 1:34 where he discusses this issue.
- Mishna Brurah 583:8. Mishna Brurah elaborates that this is symbolic of our wish to be immune to the ayin hara and that we want to be as fruitful as the fish of the sea. Mateh Ephraim 598:4-5 also says it should be done with fish, but criticizes the minhag that some have of feeding the fish crumbs of bread. The Machatzit Hashekel 583:5 also says it is forbidden to throw food into the water.
- Yalkut Yosef Moadim page 35, Sh"t Torah Lishma 145, Ben Ish Chai Netsavim 12
- Nitai Gavriel (Rosh Hashana 69:14)
- Yalkut Yosef Moadim page 35
- The Mateh Efraim 598:4 and Kitzur Shulchan Aruch 129:21. Eliya Rabba 596:3 writes based on kabbala that shaking out your pockets is like shaking off the kelipot (layers) that stick to us when we sin. Rabbi Eli Mansour points out that this is in no way a substitute for repenting, just a symbolic act to show that our repentance is sincere.
- Aruch Hashulchan 583:4 and Elef Hamagen 583:7. Rabbi Eli Mansour, Ketzeh Hamateh 598:7 and Yalkut Yosef Moadim 35 say that women aren't obligated to do tashlich and therefore shouldn't in order to prevent inappropriate mingling between genders.
- Ben Ish Chai Parashat HaNetzavim: 12 says to say it even on shabbat. Kaf Hachayim 583:31 says that is the custom in Yerushalayim. Yalkut Yosef Moadim page 35, Sh"t Yabia Omer 4:47, Sh"t Yechave Daat 1:53, Halichot Olam 2:pg. 231 say that you should do it on that day but if there is no eruv then you cannot carry a book with you. If there is a concern that people will carry books anyway, it should be done the next day. If there is an eruv however, one should do it. If one normally doesn't rely on the eruv to carry, in this case he can give it to a child to carry for him. Shvut Yaakov 3:42 quotes the Shnei Luchot Habrit that it should be postponed, but disagrees and says to say it on shabbat, and quotes the Maharil (Teshuva 136) as saying the same. This is also the ruling of the Mateh Ephraim 598:4, Shaare Teshuva 583:6. The Elef Hamagen 598:11 says to postpone it. Rabbi Eli Mansour says this is the custom of the Brooklyn Syrian Community based on the psak of Chacham Baruch ben Chaim. See Yabia Omer 4:47 and Yalkut Yosef Moadim page 34 for a summary of the opinions on this matter.
- Shulchan Aruch 597:1, Chazon Ovadyah (Yamim Noraim, pg 180)
- Mishna Brurah 597:2 writes that even though usually on Shabbat and Yom Tov one shouldn't fast until after chatzot on rosh hashana it's permissible to allow the davening to extend past chatzot. Rav Hershel Schachter on yutorah.org (min 40-42) explains that this leniency is based on the fact that there are opinions in the Geonim who even permit fasting completely on Rosh Hashana.
- Shulchan Aruch HaRav 529:5
- Chaye Adam 24:10, Sh"t Igrot Moshe 1:170, Rabbi Hershel Schachter in a shuir (min 43-45:30)
- Mishna Brurah (Shaar Hatziyun 582:4). Rav Chaim Pinchas Sheinberg in Moriah Elul 5759 22:10-12 p. 100 writes that one doesn't fulfill one's obligation since the theme of Malchut is a main theme of Shemona Esrei.
- Rav Moshe Shternbuch in Teshuvot Vihanhagot 2:268 quotes the Vilna Gaon in his Sefer Maaseh Rav 207 that it is forbidden to cry, but also quotes the Arizal (brought down in Baer Heitev 584) that any person with a good soul would cry on Rosh Hashana. He claims that they aren't disagreeing, but rather that the Vilna Gaon is talking about crying from fear of the day of judgement and viewing the day as one of sadness and gloom. But if the tears come spontaneously from a longing for Hashem during the prayers, that it praiseworthy.
- Shulchan Aruch 584:4
- Mishna Brurah 188:19 quotes the Magen Avraham 188:7 who says one doesn't repeat Birkat HaMazon and the Eliyah Rabba who argues and the Mishna Brurah leaves it unresolved. Shemirat Shabbat Kehilchata 57:7(4) quotes both opinions and in note 25 he concludes that one doesn't have to repeat benching because it's a Safek Brachot LeHakel. Similarly, Rabbi Hershel Schachter in a shuir (min 41-43) mentions that some achronim hold that one doesn't have to repeat benching because there is an opinion that one is allowed to fast on Rosh Hashana. When asked whether this would be considered Safek Deoritta Lechumra he explained that even if one forgot Yaaleh VeYavo one fulfills the Deoritta obligation of benching it just that one didn't fulfill the din derabbanan to have a meal for Yom Tov.
- S”A 582:1, Kitzur S”A 129:3
- S”A 582:2, Kitzur S”A 129:3
- S”A 582:1, Kitzur S”A 129:3
- Rama 118:1, Mishna Brurah 582:9
- S”A 582:2. Chazon Ovadyah (Yamim Noraim pg 193) writes that this is the halacha and we don't say Safek Brachot LeHakel however it is more correct to stipulate: if I'm obligated to repeat Shmoneh Esrei then I'm praying for my obligation, and if the halacha is that I don't have to repeat my prayer should be considered a voluntary prayer.
- Rav Mordechai Eliyahu in Maamer Mordechai (Aseret Yami Teshuva #19) based on Ben Ish Chai (Nitsavim #19).
- Chazon Ovadyah (Yamim Noraim pg 205)
- S”A 582:3
- Mishna Brurah 582:11 writes that if he remembers before the end of the Bracha he goes back, however, after he finishes the Bracha, there’s a dispute in the achronim. However, the Kitzur S”A 129:4 writes that unless he remembers within Toch Kedi Dibbur he doesn’t go back.
- Kitzur S”A 129:1 writes to say LeElah LeElah MeKol Birchata. Mishna Brurah 56:2, 582:16 agrees but adds a vav as follows LeElah ULeElah. Rav Mordechai Eliyahu’s footnote on Kitzur S”A 129:1 writes that the Sephardic minhag is not to change this for Aseret Yemei Teshuva.
- S”A 582:4 writes that those who have the minhag to stand bent over for Tefillot on Rosh Hashanah should stand straight at the end of the Bracha. Mishna Brurah 582:14 writes that starting from Baruch Atta Hashem through the beginning of the next Bracha one should stand erect so that it doesn’t appear like one is adding the established bows of Chazal.
- Kitzur S”A 129:2
- S”A 582:9 writes that one may daven out loud during Tefillot of Rosh Hashana and not worry about bothering others Davening since everyone has a machzor. Mishna Brurah 582:24 writes not to raise one’s voice too much.
- Kitzur S”A 129:2, Chaye Adam 139:2, Kaf HaChaim 582:17, and Rav Mordechai Eliyahu’s footnote on Kitzur S”A 129:2. Kaf HaChaim 582:17 adds that if one doesn’t have kavana another way one may raise one’s voice slightly.