[Question:]{.underline} Is it permissible to go to Confession during Sunday Mass?
[Answer]{.underline}: It has always been the custom for Confessions to be heard during Mass whenever this is possible, preferably during weekday Masses, but also during Sunday Masses. This gives some of the faithful the opportunity of going to Confession who would not otherwise easily be able to do so. A quick Confession during Sunday Mass does not interrupt the assistance at the Mass, for it is a prayer, like the Mass, and does not involve a notable part of the Mass.
However, if a person were to spend a notable part of Sunday Mass in the Confessional, for example receiving spiritual advice and direction from the priest, then he would not have filled his Sunday obligation and would have to stay for the next Mass. A person does not have the right to place himself in this situation, and he ought not to go to Confession after the Offertory or before Communion when he anticipates that the Confession might take a long time.
Furthermore, there is also the question of respect. In general the Confessor who is hearing Confessions during Mass will stop during the sermon, so that the penitents also can receive instruction, and he will also stop during the Consecration of the Mass, out of respect for this great miracle. These times should be avoided when going to Confession during any Mass.
Answered by Father Peter Scott, SSPX.