(Applied from the principles of the Salaf on cooperation in sin.) The Prophet (ﷺ) cursed the consumer of ribā, the one who pays it, the scribe of it, and its two witnesses, and said: "They are equal." Whoever writes the contract, witnesses it, processes it, or makes the system of ribā function, falls under this curse. Work in a ribā-based bank in roles that directly serve ribā transactions is forbidden. Work in roles entirely separate from ribā (security, cleaning, IT systems unrelated to interest contracts) is, by the principle of necessity and the absence of direct cooperation in the prohibited, allowed by some scholars — but the cautious one leaves it.