Is it permissible to fast the six days of Shawwal before making up the missed days of Ramadan, or is it obligatory to make them up first, and is it possible to combine the intention of making up (fasts) with the intention of fasting the six days of Shawwal?

According to the majority of scholars, it is permissible to begin fasting the six days of Shawwal before making up for missed Ramadan fasts. It is permissible without dislike according to the Hanafis, but with dislike according to the Malikis and Shafi'is. The preponderant opinion is that it is permissible without dislike, because making up for missed fasts is flexible in time, and the virtue of fasting the six days might be missed. As for combining the intention for the six days with that of making up for missed fasts, it is not valid according to the preponderant opinion.