In the month of November, and especially on All Souls Day, Nov. 2, the Church offers many opportunities for the baptized faithful in the state of grace to help the Holy Souls in Purgatory through special plenary indulgences.
Praying for the living and the dead is one of the spiritual works of mercy. Paragraph 1032 of the Catechism of the Catholic Church states:
From the beginning the Church has honored the memory of the dead and offered prayers in suffrage for them, above all the Eucharistic sacrifice, so that, thus purified, they may attain the beatific vision of God. The Church also commends almsgiving, indulgences, and works of penance undertaken on behalf of the dead…
For more information on prayers for the Holy Souls in Purgatory, including special prayers and indulgences available in November, please click on this link.