To gain a plenary indulgence, it is necessary to perform the work to which the indulgence is attached and to fulfill three conditions: sacramental Confession, Eucharistic Communion, and prayers for the intentions of the Pope. (Normally, one Our Father and one Hail Mary and Glory be suffices, though we are free to say any prayers we desire.) The three conditions may be fulfilled several days before or several days after performing the prescribed work; nevertheless. It is fitting that Communion be received and prayers for the Pope’s intentions be said the same day the works performed.
A single confession suffices for gaining several plenary indulgences, one each day over a period of days. However, to receive each plenary indulgence, one must receive Holy Communion and pray for the Pope’s intentions each time. To be properly disposed for gaining a daily plenary indulgences, one should go to Confession at least every two weeks.
Only one plenary indulgence can be acquired each day, unless a person is at the point of death. In that event, even after gaining a plenary indulgence that day, one can gain a second which is connected with the Apostolic blessing.
If one who seeks a plenary indulgence has imperfect dispositions or does not fulfill the requisite conditions after performing the prescribed work, the Church still grants him a partial remission of temporal punishment due for his sins.
A partial indulgence remits only part of the punishment due for sin, and is granted without designation of a specific “amount of time” to be remitted. Any number of partial indulgences can be acquired per day, unless otherwise indicated. To gain the indulgence, one must be in the state of grace and should strive to make his dispositions as holy and perfect as possible.