What is the ruling on financial prizes offered by banks (usurious or Islamic) in exchange for depositing a sum of money and receiving a coupon to enter a draw, with the possibility of retrieving the deposited amount at any time?

It is impermissible to deposit money in interest-based banks except in cases of extreme necessity, such as when an Islamic bank is unavailable and there is fear for one's money. This is based on the resolution of the Islamic Fiqh Academy, which prohibits dealing with interest-based banks for anyone who has access to an Islamic bank.

As for the prizes offered by interest-based banks to depositors, they are a trick to conceal usurious interest. They combine usury (riba) and gambling (maysir), both of which are forbidden.

The distributed prizes are not from the bank's own funds but are rather usurious interest distributed by means of a lottery, which is what makes them gambling.

These prizes are the very essence of usurious interest. If a person receives them, they must dispose of them by spending them on charitable causes, while also withdrawing their funds from the interest-based bank unless there is a necessity.

Depositing money in interest-based banks is, in reality, a loan from the depositor to the bank, and every loan that brings a benefit (to the lender) is unanimously forbidden.