Can he sell an item to someone who pays for it with a cheque from a riba-based bank?
Question

                I work in a company that sells electrical items as a sales representative. When I sell to the customer, he gives me a bank cheque, and each customer writes a cheque from a different bank, either riba-based or otherwise. Then I give the cheque to the accounts department, and they transfer it to the company’s account in their own bank. My question is: is dealing with these cheques regarded as participating in or helping to perpetuate riba in those banks, or consuming people’s wealth unlawfully, or supporting the banks?.
Praise be to Allah.
    There is nothing 
    wrong with accepting the payment from the purchaser in the form of a cheque, 
    even if it is from a riba-based bank, and there is nothing wrong with 
    dealing with riba-based banks in cases of necessity to protect money if 
    there is no Islamic bank, subject to the condition that the money is put in 
    non-interest-bearing accounts in those banks. Please see the answer to 
    question no. 22392. 

    Engaging in 
    transactions with people who deal with riba or put their money in riba-based 
    banks is permissible. That is indicated by the reports which prove that the 
    Prophet (blessings and peace of Allah be upon him) and his Companions 
    engaged in transactions with the Jews in Madinah although they, as Allah, 
    may He be exalted, has told us, consume unlawful wealth and take riba. 

    It is permissible 
    with you to sell to this customer who deals with riba, even if he pays from 
    his riba-based account or with a loan that he took from a riba-based bank. 

    Giving the cheque 
    to the accounts department and transferring the money to the company or to 
    the bank used by the company is not regarded as recording or writing down 
    riba; rather it is writing down and recording the price that was taken in a 
    permissible and Islamically acceptable manner. It makes no difference 
    whether the purchaser pays for it in cash or with a cheque. 

    Shaykh Ibn 
    ‘Uthaymeen (may Allah have mercy on him) said: It is permissible to engage 
    in transactions with a person who deals with riba, but those transactions 
    should be done in a proper manner. For example, it is permissible to buy 
    from this man who deals with riba, if the product is bought from him in 
    return for money, and it is permissible to take a loan from him, and there 
    is nothing wrong with that. The Prophet (blessings and peace of Allah be 
    upon him) used to engage in transactions with the Jews even though they 
    consumed haraam wealth, and he accepted gifts from them and he accepted 
    their invitations. He sold to them and bought from them. He accepted their 
    gifts, as in the story of the Jewish woman who gave him a (roasted) sheep on 
    the day of the conquest of Khaybar. And he accepted their invitations, as he 
    accepted the invitation of a Jewish boy in Madinah. And he bought food for 
    his family from a Jewish man and gave him his shield in pledge, and he died 
    when his shield was still being held in pledge. 

    To sum up, if a 
    person earns money from haraam sources, and you engage in a permissible 
    transaction with him, there is nothing wrong with you doing that.

    End quote from 
    Fataawa Noor ‘ala ad-Darb 

    And Allah knows best.