The Official Website of Grand Ayatollah Makarem Shirazi

There are circumstances in which fasting is invalidated, yet one is not required to observe kaffārah, and all one needs to do is perform the qada of the missed fast. 1. When one is doubtful in their intention of fasting, or they decide to invalidate their fast, however, they do not commit any acts which invalidates the fasting, or make an intention of fasting to show off. 2. If one, without having investigated about fajr arrival, does something that invalidates fast in the month of Ramadan, and they come to know later that it was time for fajr, they should make up for this fast. Even if they investigate, however, they are still doubtful whether or not its fajr time they should make up for the fast. 3. When another person has said that it is fajr time, but one does not have certainty about it, or assumes that the person is just kidding, and therefore does the invalidators of fast, or when one asks an unreliable person about fajr time, and does one of the fast invalidators on account of what that person has said, and then they later come to know that the time of fajr adhān had arrived. 4. If a truthful person informs one about the arrival of the time of Maghreb, and depending on that, one breaks their fast, but they come to know later that Maghreb had not yet arrived. 5. When due to darkness in the clear sky, one becomes certain that Maghreb has arrived, and therefore break their fast, and then they find out that it was not yet Maghreb. 6. When one rinses out their mouth to cool themselves off or without any purpose, and some water is swallowed involuntarily. 7. When one has a wet dream at night in the month of Ramadan, and goes back to sleep after that, and then wakes up and goes back to sleep for the second or third time, and does not wake up before fajr, in which case the obligatory precaution demands that they only make up for the missed fast, but if he goes to sleep and wakes up after the fajr adhān, their fast is valid. 8. Based on obligatory precaution, when one forgets to perform ghusl after Janābah, ritual impurity, and fasts in a state of Janābah. 9. When a man has lawful courtship with his wife, but he is not certain that what he is doing will not result in the discharge of semen, and it in fact does not result in ejaculation, in which case only qada is due on him.