Having an interest-based credit card in cases of necessity
Question

                In my area one of the requirements for renting a car is to have a credit      card. You don't have to charge anything on the card, you just must present it for safety precautions. When the car is returned you can pay cash and nothing is ever charge to the card. So, I would like to know, is it halal to get a credit card for this purpose.
Praise be to Allah.The basic principle is that interest-based transactions are haraam and
    it is not permissible to engage in them. This includes the conditions mentioned in the
    contracts for credit cards. In some countries they rely a great deal on these credit
    cards, and you can hardly find anyone who does not use them. We put the following question
    to Shaykh Muhammad ibn Saalih al-Uthaymeen:
Credit cards include conditions based on riba (interest/usury) 
    if you delay payments, they charge an extra penalty. But in the place where I live in
    America, I cannot rent a car or a shop or use many other services unless I have a credit
    card. If I do not use a credit card, I will suffer unbearable hardship. If I commit myself
    to make the payments within a certain time limit, so that I do not have to pay the
    interest charges, will this allow me to have a credit card and thus relieve some of the
    hardship I am facing?
The shaykh, may Allaah preserve him, answered as follows:
If the hardship he is facing is certain, and the likelihood that he
    will delay payments is remote, then I hope there is nothing wrong with him having the
    credit card.
Question:
Do the conditions relating to interest make a transaction invalid or
    not?
Answer:
If a contract contains an invalid condition, this
    does not invalidate the entire contract, for a number of reasons: (1) necessity, (2)
    because it does not really affect anything. The man thinks that he is going to make the
    payments before interest is due. Because this is more likely than the condition of having
    to pay interest, and because it is necessary  which is the main point  I hope
    that there is nothing wrong with it. We have a definite matter  necessity  and
    a matter which is not necessarily going to happen  which is delay in payment 
    and the matter that is definite takes precedence over something which may not even happen.
    And Allaah knows best.