Short answer
Yes. Suhoor is a sunnah, not a condition of the fast, so if you oversleep you still fast that day. In the Hanafi school the intention can be made after you wake, as long as it is before midday and you have not eaten. If you ate after fajr had begun without realising, the fast is broken: you make up that day and still hold back from food for the rest of it.
Suhoor is sunnah and full of blessing, but missing it does not affect the fast. A person who wakes after true dawn in Ramadan makes the intention and fasts. Eating or drinking after true dawn while thinking it was still night breaks the fast with qada only, and the person must hold back for the rest of the day. Eating while unsure whether dawn has come is makruh.
Other madhhabs
- Shafi'i
- If you slept through the night without forming any intention to fast, that day's Ramadan fast is not valid: you must still hold back from food and make the day up.
- Hanbali
- If no intention was made at night, the Ramadan fast of that day is not valid: you hold back from food and make it up.
Explanation
The Prophet ﷺ encouraged suhoor because there is blessing in it, but the fast itself depends on the intention and on holding back from dawn to sunset. Missing the meal makes the day harder, not invalid.
You probably intended already. If you went to sleep planning to fast the next day, that plan is your intention, in every school. So even by the stricter Shafi'i and Hanbali rule, most people who oversleep have a valid fast. In the Hanafi school, even a person who had made no plan at all can intend in the morning.
Eating after fajr began. Fajr starts at true dawn, not at sunrise. If you wake late and eat, then find out that fajr had already come in, the fast of that day is broken by mistake. You stop eating immediately, keep away from food and drink until sunset out of respect for Ramadan, and make up one day later. There is no kaffarah.
- Follow a reliable timetable for your city and stop eating when fajr begins.
- Do not wait for the end of a late adhan if the timetable says fajr has started.
- If you are unsure, stop: eating in doubt is disliked.
For suhoor times and sunnahs, see suhoor in Ramadan. For the intention, see niyyah for fasting.
The evidence
Quran, Surah Al-Baqara 2:187
أُحِلَّ لَكُمْ لَيْلَةَ ٱلصِّيَامِ ٱلرَّفَثُ إِلَىٰ نِسَآئِكُمْ ۚ هُنَّ لِبَاسٌۭ لَّكُمْ وَأَنتُمْ لِبَاسٌۭ لَّهُنَّ ۗ عَلِمَ ٱللَّهُ أَنَّكُمْ كُنتُمْ تَخْتَانُونَ أَنفُسَكُمْ فَتَابَ عَلَيْكُمْ وَعَفَا عَنكُمْ ۖ فَٱلْـَٰٔنَ بَٰشِرُوهُنَّ وَٱبْتَغُوا۟ مَا كَتَبَ ٱللَّهُ لَكُمْ ۚ وَكُلُوا۟ وَٱشْرَبُوا۟ حَتَّىٰ يَتَبَيَّنَ لَكُمُ ٱلْخَيْطُ ٱلْأَبْيَضُ مِنَ ٱلْخَيْطِ ٱلْأَسْوَدِ مِنَ ٱلْفَجْرِ ۖ ثُمَّ أَتِمُّوا۟ ٱلصِّيَامَ إِلَى ٱلَّيْلِ ۚ وَلَا تُبَٰشِرُوهُنَّ وَأَنتُمْ عَٰكِفُونَ فِى ٱلْمَسَٰجِدِ ۗ تِلْكَ حُدُودُ ٱللَّهِ فَلَا تَقْرَبُوهَا ۗ كَذَٰلِكَ يُبَيِّنُ ٱللَّهُ ءَايَٰتِهِۦ لِلنَّاسِ لَعَلَّهُمْ يَتَّقُونَ ﴿١٨٧﴾
It has been made permissible for you the night preceding fasting to go to your wives [for sexual relations]. They are clothing for you and you are clothing for them. Allah knows that you used to deceive yourselves, so He accepted your repentance and forgave you. So now, have relations with them and seek that which Allah has decreed for you. And eat and drink until the white thread of dawn becomes distinct to you from the black thread [of night]. Then complete the fast until the sunset. And do not have relations with them as long as you are staying for worship in the mosques. These are the limits [set by] Allah, so do not approach them. Thus does Allah make clear His ordinances to the people that they may become righteous.
Eating is allowed until true dawn, and the fast begins from that point.
Sahih al-Bukhari 1923
Sahih... تسحروا فإن في السحور بركة ...
"Eat suhoor, for in suhoor there is blessing."
Suhoor is a recommended sunnah, not a condition for the fast.
Where the ruling is recorded
- al-Hidaya, Kitab al-Sawm, chapter on what requires qada and kaffarah. Whoever eats thinking it is still night, and it turns out dawn had come, makes up the day without kaffarah.
- al-Durr al-Mukhtar, Kitab al-Sawm, section on those who must hold back for the rest of the day. One whose fast broke by mistake in Ramadan holds back for the remainder of the day.
- Minhaj al-Talibin, Kitab al-Siyam. The Shafi'i requirement of a night intention for obligatory fasts.
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.