Is the investment deposit at Kuwait Finance House, in which the bank guarantees the principal amount after one year, and the profits are unknown before the year-end and no profits are calculated if withdrawn before the year-end, permissible in Sharia, and what are its conditions?

It is permissible to deal with Islamic banks if they adhere to Sharia (definition) guidelines, and their deposits are considered Mudarabah (definition) (profit-sharing). However, the mentioned transaction has two issues: First, the non-calculation of profits when money is withdrawn before the year's end unless it is stipulated and agreed upon. Second, the condition of guaranteeing the capital is invalid in Mudarabah, because losses are borne by the capital, and profits are distributed according to the agreement.