In the payment systems glossary, some terms are essential. One of them is the term Onus. Onus literally means "on us." In payment systems, it refers to a situation where the card-issuing bank and the POS/ATM bank are the same.
Why does it matter whether a transaction is Onus?
If a transaction is Not Onus, settlement of the transaction is carried out through clearing, and the POS/ATM bank has to pay a commission to the card-issuing bank. The card-issuing bank, in turn, charges the cardholder a commission at a certain rate based on the transaction amount. (For example, in an ATM cash withdrawal, the customer is charged a commission of 1% + 0.91 TL.)
In Onus transactions, the cardholder pays no commission at all, and no clearing commission is paid under any circumstances. For this reason, banks pay close attention to having their transactions take place as Onus in order to increase their profitability.
The flow of an Onus transaction
In an Onus transaction, the card and the POS belong to the same bank; the transaction never leaves the bank and does not require clearing. For this reason, it is generally faster and lower-cost.
The bank approves these transactions within its own system, records them in its own accounts, and no commission needs to be shared.
Banks can pass this advantage on to customers by giving extra points or installments on transactions that go through their own POS terminals. Software teams perform the Onus check using the BIN table.
