This heroic Act of Charity in behalf of the Souls in Purgatory consists in the voluntary offering made for their relief, of all our works of satisfaction during life, as well as of all suffrages which may be offered for us after death.  This offering we place in the hands of the Blessed Virgin Mary, that she may distribute its merits to those holy Souls whom it is her good pleasure to deliver from the pains of Purgatory.

Let it be understood, however, that we offer hereby only the special and personal portion of the satisfactory merit of our good works, so that we are not prevented from offering our good works, prayers, the Holy Sacrifice of the Mass, etc. for other intentions.  It is also to be remembered that, though this act is sometimes called a vow, yet it induces no obligation binding under sin.

The following indulgences were granted to those who make this heroic offering: Pope Benedict XIII, Aug. 23, 1728, made the first grant of indulgences for this act.  Pius VI, Dec. 12, 1788, afterwards confirmed it, and Pius IX again renewed and specified the indulgences in a decree dated September 30, 1852, November 20, 1854; St. Pius X, Feb. 20, 1907.

I.    All priests who take this vow have the indult of a privileged altar, personally, every day of the year, at whatever altar they celebrate Mass for the faithful departed.

II.    All the faithful who have made this obligation can gain a Plenary Indulgence, applicable only to the Souls in Purgatory, every time they receive Holy Communion, provided they visit a church or public oratory and pray according to the intention of the Sovereign Pontiff.

III.    All the faithful who have made this obligation can apply a Plenary Indulgence to the faithful departed every Monday, by hearing Mass for this intention, provided they go to Holy Communion and visit some church and pray to the intention of the Sovereign Pontiff.

IV.    All indulgences granted, or to be granted, even though not stated as applicable to the departed when gained by those who have made this obligation, can be applied to the Souls in Purgatory.

V.    For those whose duties prevent their hearing Mass on Monday, the Mass heard on Sunday is sufficient to gain the Indulgence No. III.

For those who do not yet approach the holy table, or who are unable to receive Holy Communion, some other good work may be appointed by confessors, authorized by their respective bishops, to gain the Plenary Indulgence as above.

O eternal and most merciful Father, accept the oblation which I make to Thee, in union with the Most Sacred Heart of Thy Divine Son Jesus, of all the merits of the life, sufferings, and death of the same Jesus, our Lord and Saviour, in behalf of the Souls suffering in Purgatory.  I offer to Thee, O heavenly Father, for their deliverance from suffering, for their admission to the joys of Heaven, the infinite merits of the Sacred Heart of Jesus, the immense and superabundant merits of the ever-blessed Virgin Mary, of all the holy martyrs, and of all the saints in Heaven and on earth.

I offer also, and resign entirely, in favour of those suffering Souls, all my satisfactory works, and those of others applied to me in life or death, and after my passage to eternity; and in order to render this poor offering of mine more acceptable to Thee, and more beneficial to the Souls for whom I make it, I unite it to the infinite and most pleasing homage which the Divine Heart of Jesus is continually paying to Thy Majesty.  I place it in the most pure hands of Mary Immaculate, that she may present it to Thee as a pleasing holocaust, and distribute according to her good pleasure the graces, favours and relief obtained from Thine infinite mercy.

Note: It is not necessary to make use of this set formula, since in order to share in the said indulgence no more is required than a heartfelt act of the will.