Is it permissible to deal with banks or financial institutions that charge a commission (2-5%) for guaranteeing a debt for construction contractors who receive 50% of the project costs in advance from the state without interest, in order to repay the debt if the project stops or the contracting company goes bankrupt?

It is not permissible to obtain a guarantee from a bank or financial institutions if it stipulates the payment of money in return for that guarantee, because it ultimately becomes a loan that brings a benefit. This has been stated in Al-Insaf, that making a fee for a guarantee is not permissible, because he is a guarantor, and thus it becomes a loan that brings a benefit.