Ribā in Loan/Transaction
Ribā in loan is the extra amount paid by the borrower to the lender as stipulated in the loan deed. 
Ribā arising from a sale transaction is to sell an item — normally sold by weight/ volume — in exchange for something of the same category in Islamic law plus extra.

Ribā-bearing Loan
It is ḥarām to get a ribā-bearing loan. However, the very loan deed is valid, [i.e. the borrower owns the money borrowed].In urgent situations, one can - for escaping committing a ḥarām act – intend, at the time of borrowing, not to give the extra amount even though he knows that they would eventually take it from him.

Superficial Transaction
If someone sells their property with the condition of buying the same later from the buyer at a higher price, it is ḥarām and void because it is not really intended and it serves as a means to obtain a ribā-bearing loan. However, if the sale is concluded seriously, in a shar‘ī way and without stipulating to buy it again, there is no harm in buying the property back from the buyer later for the same price or even at a higher one in cash or in credit.

Facilitating a Ribā-bearing Loan
Any work that contributes, in any way, to concluding, processing, finalizing a ribā-bearing loan, or collecting the ribā from the borrower, such as writing down the deed, and keeping and auditing the accounts, is ḥarām; and the worker is not entitled to a wage for such work.