What to do when you make a mistake in salah?
It is narrated by Sayyidina Abdullah ibn Ja'far (RA) that the Prophet (Sallallaho Alaihe Wassallam) said: “Anyone who has doubt in his prayer should make Sajda Sahw after giving the salutation.” Sahu means forgetfulness.
If you unintentionally commit a mistake in Waajib of Salah then you can rectify this mistake by performing Sajda Sahw. If you commit a mistake which is not included in Wajib acts of the prayer then, just seek forgiveness from Allah. There is no need to perform forgetfulness prostration Sajda Sahu. Your prayers will Insha'Allah be valid and no rectification will be needed.
Rules regarding Sajda Sahw in Islam
If one or many of the wajib acts of Salah is omitted unintentionally then it becomes wajib to make Sajda Sahw. By performing Sajda Sahu, the prayer becomes valid. If one does not perform it, he has to repeat the prayer. Recommended: 14 Wajib Acts during Salah omission of which requires Sajda Sahw
If one forgetfully leaves an act which is obligatory and a fardh act of prayer, then prayer will not become valid by performing Sajda Sahw. One must repeat it. Recommended: 6 Fard Acts during Salah omission of which invalidates the Salah
The forgetfulness prostration Sajda Sahw become wajib if a person does any mistake unintentionally. But if a person intentionally omits anything and done those mistakes then Sajda Sahu won’t become wajib. And he has to repeat his prayer. Even if doing Sajda Sahu doesn’t make any difference, the prayer will still be invalid
20 mistakes in Salah which need to be rectified by Sajda Sahw
1-If a person forgetfully recites At-tiyaat, Darood and Dua but before making salaam, he remembers that he has to make Sajda Sahw, even then he can perform Sajda Sahu, the prayer will be valid.
2-If a person has performed 2 rukus or 3 Sajdahs by mistake, and then it is wajib for him to make the forgetfulness prostration Sajda Sahw to validate his prayer.
3-While in prayer, a person recites another surah instead of Surah Faatihah, or he recited some other surah first before reciting Surah Faatihah, in these situations Sajda Sahw will be wajib.
4-In a fard salah having more than two Rakat in total, if anyone forgets to recite a surah after he is done with recitation of al Fatiha, in the first two Rakats, it is obligatory upon him to do the recitation of surah in the remaining Rakats and he has to do forgetful prostration Sajda Sahw as well.
5-If he mistakenly forgets to recite another Surah in one Rakat of the fard prayer, then he has to recite it in one of later two units and also perform Sajda Sahw.
6-If he forgets to recite another Surah in the whole prayer in all Rakats, and he just gets to know about it while he is reciting the at-tahiyyaat, he needs to make forgetfulness prostration Sajda Sahw to make prayer valid.
7-It is wajib that a person should recite another Surah after reciting Surah Faatihah in all the units (Rakats) of Sunnah and nafl prayers. If a person unintentionally omits to recite another Surah in any of the Rakats, he will have to make Sajda Sahw.
8-If a person pause in prayer so long that, in that extension of time, one could recite Sub'haanallah three times, then forgetfulness prostration Sajda Sahw become wajib. For example, if a person after reciting Surah Faatihah, began to think about as to which Surah he should recite now and his silence took so long that three times Sub'haanallah could be recited easily, then Sajda Sahu will become necessary.
If a person has a doubt in mind regarding the number of Rakat he has prayed and he kept thinking about it silently in the prayer and took so long that three times Sub'haanallah could be recited at that time. Even in this situation, it will become wajib or necessary to do Sajda Sahu.
A person recited Surah Faatihah and another Surah, but after that, he starts thinking about something unintentionally. He paused for so long to go into ruku that at that extent of time, three times Sub'haanallah could be recited. Then Sajda Sahu will become necessary to validate the Salah.
9-In a 3 or four Rakat of fardh prayer (irrespective of whether or not it's a prayer that he's offering for that time or having qada of a missed prayer, or it's a witr prayer or the first 4 Rakats of Sunnah of zuhr prayer) once the person sat for the at-tahiyyaat within the second Rakat, he unintentionally recited at-tahiyyaat twice. Even then Sajda Sahw will be wajib for him
10-A person mistakenly recited something else or Surah Fatihah instead of At-Tahiyaat, Sajda Sahw will be required
11-A person forgets to sit in the second Rakat for the At-Tahiyaat in a 3 or 4 Rakat prayers and stands up directly for the 3rd Rakat. When he realized his mistake, he was almost in a standing posture then he should not sit down again.
Rather, he should complete his prayer and should sit in the last Rakat only. In this situation, Sajda Sahw will be wajib. In case if he stands up and then goes back to sit down; he still commits a sin and he has to make Sajda Sahu.
12-Sajda Sahw will become wajib in a situation where a person is offering nafl prayer having four Rakat and he unintentionally omits to sit down in the second Rakat, then as soon as he remembers he should sit for At-tahiyaat before the Sajdahs for the third Rakat. If he realizes about it after the third Rakat, he should continue his prayer and perform Sajda Sahu at the end.
13-If a person forgets about the number of Rakat and instead of sitting down in the 4th Rakat he almost stands up. If a person stands up properly, even after that he should sit down. Even if a person has recited Surah Faatihah and the other Surah, and is in ruku, still he should sit down, recite at-tahiyyaat and then do Sajda Sahw.
14-Similarly, if a person forgets about the number of Rakat and sits down in the fourth Rakat to recite at-tahiyyaat and after that, he stands up. In this case, he must sit down as long as he remembers before making the fifth Rakat Sajdahs. When he knows about his mistake, he should sit down immediately, instead of reciting at-tahiyyaat, he should straight go for Sajda Sahw.
15-In case of confusion between the numbers of Rakats he has performed, he has to repeat his prayer, if this confusion was coincidental. But if these sorts of uncertainties happen rather frequently, he should see what his heart felt. But if after thinking about the matter, his mind is still not satisfied, then he should consider this matter as if he offered 3 Rakats and then offer one more Rakat. But he should make Sajda Sahw.
If a person has a doubt about the number of Rakats after completing prayer, then he should not bother about this doubt, his prayer is valid. But if he undoubtedly remembers that only three Rakats are offered by him, and then he should immediately stand up and add one more Rakat and also do Sajda Sahu. But if he does any act(s) which breaks the prayer such as talking to someone then he will repeat his prayer.
16-In a prayer having three or four Rakats, if a person mistakenly made salaam after the Tashadudd in the second Rakat, he should stand up for the third Rakat straightaway and finish his prayer and also it makes Sajda Sahw wajib. But, if after salaam, he did any act which nullifies prayer, he has to repeat it.
17-If a person involuntarily started recitation of dua’e qunoot in the first two Rakats instead of the third Rakat of witr prayer, he has to recite the qunoot in the third Rakat and it is also obligatory to do forgetfulness prostration Sajda Sahw to complete the prayer.
18-While offering witr prayer, if a person had confused in between second or third Rakat. And he can’t satisfy his mind. Then he should recite dua-e-qunoot in the Rakat he is offering and after sitting down and recite at-tahiyyaat he should stand to add one more Rakat. He should also recite dua-e-qunoot in this Rakat as well. In the end, he has to make Sajda Sahw.
19-Reciting dua-e-aunoot in witr prayer is wajib. If a person forgets to recite it in witr prayer, Sajda Sahw will become wajib.
20-In the fajr, maghrib, and isha prayer, the recitation should be in loud voice and zuhr and asar prayers should be offered silently. So if a person as an imam offered a prayer in a loud voice which should be offered silently, Sajda Sahw will become Wajib. Similarly, vice versa, if an imam offers a prayer silently, which should be performed in a loud voice, and then he has to make Sajda Sahu. But if very little qira'at such as one or two words are made aloud in silent prayer, and then the forgetfulness prostration Sajda Sahu won’t become wajib.
Source: Central Mosque