Najafi Q&A: Insurance

Banks and financial companies provide credit cards (such as Visa, MasterCard, etc.) that enable the cardholder to do two things: 1.To make purchases throughout the month based on credit, balance, and the cardholder’s clean financial record. However, if the full amount is not paid at the end of the month and is instead paid in installments, interest will be charged. 2.To be granted a certain sum of money (sometimes offered without the customer requesting it) for purposes such as trading, investing, expanding the home, or supporting one’s family, based on a clean financial record, consistent work, and regular installment payments, but interest will be charged, even if sometimes very minimal. What is the Sharia ruling regarding the permissibility of such transactions and paying interest in the two cases mentioned?