One may miss fasts during the month of Ramadan due to a variety of reasons; old age, illness, being a traveller etc. When this happens out of necessity, the person has to make up his fasts as soon as possible for the days missed or pay the Fidayah (donation made by the ill and old) for the missed fasts by feeding a person for the said number of days. Or one who simply decides to deliberately miss the fast for that day, he must fast 60 days or feed 60 people for each day missed (Kaffarah).

Prophet Muhammed (SAW) said: "The person who abandons one's fast during the month of Ramadan without a genuine reason or illness, cannot recompense for it even if he fasts throughout the rest of his life." - Abu Dawud

There are a few regulations pertaining to making up of missed fasts.

1. It must be observed as soon as possible.
2. One does not have to make up the missed fasts continuously.
3. Obligatory fasts must be observed before making up missed fasts.
4. If one cannot observe the fasts that was deliberately broken, then he or she must feed 60 persons for each day missed, preferably on the same day. It isn't acceptable to feed the same individual for 60 days.
5. If Fidiyah is paid by one who was ill but regains health, he or she should make up the fast with the hope that Allah accepts the reward of the Fidiyah.
6. The family cannot make up fast for the one who passes away, but can pay the Fidiyah so far it doesn't pass 1/3 the value of the property of the deceased.

"(Fast) a certain number of days; and (for) him who is sick among you, or on a journey, (the same) number of other days are to be made up; and for those who can afford it there is a ransom: the feeding of a poor person (each day) - but whoever does more good of his own accord, it is better for him. But to fast is best for you, if only you knew." - Q2:184