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

I work in a company thatsells 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 givethe 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 Allaah.
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 incases of
necessity to protect money if there isno Islamic bank, subject to the
condition that themoney is put in non-interest-bearing accounts in
those banks. Please see the answer to question no. 22392 .
Engaging in transactionswith people who deal with riba or put their
money in riba-based banks is permissible. That is indicated by the
reports which prove thatthe 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 youto 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 theaccounts 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 downand 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 intransactions 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 dealswith riba, if
the product is bought from him in return for money, and it is
permissible to take a loan from him, and thereis 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 boughtfood 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 youengage
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.