All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.
As long as the missed fast-days for which you need to make up were all missed during the month of Ramadan, then they are all equal and no category is given priority over the other. We have not found any scholarly opinion giving precedence to any of these categories over the others.
The jurists, however, gave precedence to making up for missed fast-days of Ramadan over the fulfillment of a vow (to observe fasting). However, they maintained that the reason for missing the fast-days during Ramadan is irrelevant in this regard. They held, though, that only making up for the missed fast-days during Ramadan should be given precedence over fasting as expiation. Ibn ‘Aabideen wrote, “The author gave precedence to making up for the missed fast-days during Ramadan to indicate that it should be given precedence over fasting as expiation.”
However, if those fast-days were missed during different months of Ramadan and not during the same month, some jurists maintained that the person should specify in his intention that he is making up for the missed fast-days in Ramadan of such-and-such year. Al-Mawsoo‘ah Al-Fiqhiyyah (Fiqh Encyclopedia) reads: “When a person is making up for missed fast-days in two different months of Ramadan, the fasting is not valid unless the person specifies in his intention that he is making up for the missed fast-days in Ramadan of such-and-such year.”
Other jurists held that the specification in the intention is not necessary because the missed fast-days belong to the same category (that is, they were missed during Ramadan in general). Al-Ansaari said in his book Asna Al-Mataalib: “It is permissible for a person who is liable for making up for missed fast-days in two months of Ramadan to hold the intention to observe fasting on a given day to make up for a missed fast day (without specifying which month of the two) because the missed fasts belong to the same category…” Perhaps this opinion is easier.
We would like to point out that the major expiation for breaking the fasting of Ramadan is due only in case of having sexual intercourse during the daytime of Ramadan according to the majority of Muslim scholars.
If you could not make up for all the missed fast-days before the coming Ramadan, then you can continue after Ramadan; please refer to Fataawa 82013 and 82187 about the gravity of violating the sanctity of Ramadan by breaking the fasting deliberately and that it is incumbent on the doer to repent to Allaah of such a sin and make up for that day. This is contrary to the other opinion suggesting that such an act entails major expiation.
Also, refer to Fatwa 84189 about the expiation for breaking the fasting of Ramadan by having intercourse in daytime and Fatwa 83400 about the impermissibility of delaying making up for the missed days of Ramadan until the following Ramadan without a valid excuse. If there is an excuse, you are obliged to make up all the missed days and make expiation for each day missed by feeding a poor person. Also, refer to Fatwa 86527 about the conditions of sincere repentance.
Finally, if you make sincere repentance and start making up for the missed fast-days, then we hope that this would be a reason for being blessed with success and the help of your Lord in forsaking sins and misdeeds in Ramadan and other months and that your past negligence will not affect your deeds after your repentance.
Allaah Knows best.