Short answer
If you ate or drank because you forgot you were fasting, your fast is still valid: stop as soon as you remember and carry on, with nothing to make up. If it was a mistake while you knew you were fasting, such as water slipping down during wudu, the Hanafi school counts the fast as broken and you make up one day.
Eating, drinking or intercourse out of genuine forgetfulness does not break the fast, whether it is a Ramadan, qada or voluntary fast. Spit out what is in your mouth once you remember; carrying on after remembering breaks the fast. An error while aware of the fast, or eating because you wrongly thought it was still night or that the sun had set, breaks the fast with qada only.
Other madhhabs
- Shafi'i
- Water that slips down the throat during an ordinary rinse in wudu, and food a person is forced to eat, do not break the fast.
- Maliki
- Eating out of forgetfulness breaks an obligatory fast: you keep fasting that day and make it up later. A voluntary fast is not broken by it.
- Hanbali
- Water that slips down during wudu, and being forced to eat or drink, do not break the fast. Intercourse out of forgetfulness breaks a Ramadan fast and requires kaffarah.
Explanation
The Prophet ﷺ said that someone who forgets and eats or drinks should complete the fast, because it was Allah who fed them and gave them drink. So a forgetful sip of water is not your fault and costs you nothing. The Hanafi, Shafi'i and Hanbali schools apply this to every kind of fast.
Forgetting is different from a mistake. In the Hanafi school the excuse is for forgetting that you are fasting. If you knew you were fasting and something went down by accident, the fast is broken and you make up one day, without kaffarah. Examples:
- Water slipping down your throat while rinsing your mouth in wudu.
- Eating after fajr had begun because you thought it was still night.
- Breaking the fast before sunset because you thought the sun had set.
- Being forced to eat or drink.
In these cases you still hold back from food for the rest of the day out of respect for Ramadan, then make up the day later. If you see someone eating who seems to have forgotten, remind them gently.
For suhoor timing mistakes, see is your fast valid if you miss suhoor. For the full list, use the what breaks your fast checker.
The evidence
Quran, Surah Al-Baqara 2:286
لَا يُكَلِّفُ ٱللَّهُ نَفْسًا إِلَّا وُسْعَهَا ۚ لَهَا مَا كَسَبَتْ وَعَلَيْهَا مَا ٱكْتَسَبَتْ ۗ رَبَّنَا لَا تُؤَاخِذْنَآ إِن نَّسِينَآ أَوْ أَخْطَأْنَا ۚ رَبَّنَا وَلَا تَحْمِلْ عَلَيْنَآ إِصْرًۭا كَمَا حَمَلْتَهُۥ عَلَى ٱلَّذِينَ مِن قَبْلِنَا ۚ رَبَّنَا وَلَا تُحَمِّلْنَا مَا لَا طَاقَةَ لَنَا بِهِۦ ۖ وَٱعْفُ عَنَّا وَٱغْفِرْ لَنَا وَٱرْحَمْنَآ ۚ أَنتَ مَوْلَىٰنَا فَٱنصُرْنَا عَلَى ٱلْقَوْمِ ٱلْكَٰفِرِينَ ﴿٢٨٦﴾
Allah does not charge a soul except [with that within] its capacity. It will have [the consequence of] what [good] it has gained, and it will bear [the consequence of] what [evil] it has earned. "Our Lord, do not impose blame upon us if we have forgotten or erred. Our Lord, and lay not upon us a burden like that which You laid upon those before us. Our Lord, and burden us not with that which we have no ability to bear. And pardon us; and forgive us; and have mercy upon us. You are our protector, so give us victory over the disbelieving people."
There is no sin in forgetting or erring; whether a make-up is owed is a separate question answered by the hadith and the jurists.
Sahih al-Bukhari 1933
Sahih... إذا نسي فأكل وشرب فليتم صومه فإنما أطعمه الله وسقاه ...
"If someone forgets and eats or drinks, let him complete his fast, for it was Allah who fed him and gave him drink."
Forgetful eating and drinking do not break the fast.
Where the ruling is recorded
- al-Hidaya, Kitab al-Sawm, chapter on what requires qada and kaffarah. Forgetful eating does not break the fast; a mistake, such as water entering the throat while rinsing, does, with qada only.
- al-Durr al-Mukhtar, Kitab al-Sawm, chapter on what breaks the fast and what does not. Eating while thinking it is night, when it was day, requires qada and holding back for the rest of the day.
- Mukhtasar Khalil with al-Sharh al-Kabir, Bab al-Siyam. The Maliki view that forgetful eating in an obligatory fast requires qada.
This answer is pending review by the scholars on our team. 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.