Wealth taken unjustly from a specific identifiable person — theft, fraud, deceit in a sale — must be returned to its owner or his heirs, and if that is genuinely impossible it is given in charity on his behalf, since a wrong against a servant is not lifted by repentance alone. Wealth earned from a transaction that was forbidden in itself but consensual (interest income, wages from selling alcohol, gambling winnings), where no specific person was wronged, is not kept and enjoyed: the majority direct that it be disposed of to the poor or to public benefit without intending reward, as one is only ridding oneself of filth. But whatever was consumed or spent before you knew, before you repented, or before you accepted Islam is pardoned and need not be reconstructed. Allah says, "So whoever has received an admonition from his Lord and desists may keep what is past" (Qurʾan 2:275); the Prophet ﷺ said, "Islam demolishes what came before it," and warned, "Whoever has wronged his brother in his honour or anything else, let him seek his pardon today, before there is neither dinar nor dirham."
Q&A · Business & Finance
I repented from a haram job (or newly embraced Islam) — what do I do with the money I already earned?
Evidence — the daleel
On deen2u
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.