Short answer
In the Hanafi school adding a surah after al-Fatiha is wajib in the first two rakats of a fard prayer and in every rakah of witr, sunnah and nafl. If you forget it, the prayer is still valid: do sajdah sahw at the end. If you remember while still standing, recite it then. In the third and fourth rakats of a fard prayer no surah is needed.
Joining a surah, or at least three short verses or one long verse, to al-Fatiha is wajib in the rakats named. Forgetting it calls for sajdah sahw. If you remember in ruku, Hanafi texts say to return to standing, recite it and repeat the ruku, then do sajdah sahw; if you remember later, just do sahw at the end.
Other madhhabs
- Shafi'i
- Reciting a surah after al-Fatiha is sunnah, so forgetting it needs no sajdah sahw.
- Maliki
- Reciting a surah is sunnah; forgetting it is made up with sajdah sahw before the salam.
- Hanbali
- Reciting a surah is sunnah; sajdah sahw for forgetting it is allowed but not required.
Explanation
Abu Qatadah reported that the Prophet ﷺ recited al-Fatiha and a surah in each of the first two rakats of Dhuhr, and al-Fatiha alone in the last two. Hanafi scholars treat joining a surah in those first two rakats as wajib, so missing it by mistake is repaired with sajdah sahw.
Where it is needed:
- First two rakats of every fard prayer.
- Every rakah of witr, sunnah and nafl prayers.
- Not the third and fourth rakats of a fard: al-Fatiha alone is the sunnah there. If you add a surah in them by mistake, no sahw is needed.
What to do, by when you remember:
- Still standing: recite the surah, then carry on. If you had moved on noticeably, do sahw at the end.
- In ruku: the Hanafi texts say to return to standing, recite the surah and redo the ruku, then do sahw at the end.
- After ruku: carry on and do sahw at the end.
- After the salam, before doing anything that cuts the prayer: do the sahw then; see forgetting sajdah sahw.
Related slips: reciting the surah before al-Fatiha, or reciting al-Fatiha twice before the surah, also calls for sahw in the Hanafi school. Behind an imam, you do not recite anything yourself, so none of this applies to you; see reciting al-Fatiha behind the imam. For which surahs to choose, see which surah to recite in salah and short surahs for salah.
The evidence
Sahih al-Bukhari 776
Sahih... يقرأ في الظهر في الأوليين بأم الكتاب وسورتين ...
"He recited in the first two rakats of Dhuhr al-Fatiha and a surah in each, and in the last two al-Fatiha alone."
A surah is added in the first two rakats of the fard, not the last two.
Where the ruling is recorded
- Nur al-Idah with Maraqi al-Falah, Chapter on the wajibs of the prayer and chapter on sajdah sahw. Joining a surah to al-Fatiha in the stated rakats is wajib; leaving it by mistake requires sahw.
- al-Fatawa al-Hindiyya, Kitab al-Salah, chapter on sajdah sahw. If he forgets the surah and remembers in ruku, he returns, recites and repeats the ruku, and does sahw.
Checked by our team. For a more accurate answer to your own situation, consult a scholar. Quran translation by Sahih International. Hadith Arabic from the standard editions of the six books and the Muwatta, with gradings as recorded there; the English is our own rendering. Spotted a mistake? Tell us.