Is it a sin and against my Catholic religion to file for bankruptcy? Does it violate the Seventh Commandment: Thou shalt not steal?
No, it is not a sin, presuming that you do nothing illegal to hide your financial assets and that you cooperate with the relevant civil laws about bankruptcy.
Most countries and states have set up laws—and in some cases special courts—to deal with bankruptcy cases. This is a distressing situation for everyone involved and may take years to resolve through the designated legal procedure.
In the Catechism of the Catholic Church, we read: “The seventh commandment forbids unjustly taking or keeping the goods of one’s neighbor[s] and wronging [them] in any way with respect to [their] goods. It commands justice and charity in the care of earthly goods and the fruits of [human] labor. For the sake of the common good, it requires respect for the universal destination of goods and respect for the right to private property. Christian life strives to order this world’s goods to God and to fraternal charity” (2401).