F32-ACQUIRING INSTITUTION IDENTIFICATION CODE: This is the acquirer bank ID information. It is 11 digits long.
The values it can take for domestic transactions and by card brand are as follows:
- Domestic: 00xxxx0000 (xxxx=Acquirer TCMB No)
- AmEx: 3 + 1792000051
- Visa: Acquirer Visa Main BIN (A value, starting with 4, is expected) MasterCard: 5 + Acquirer MasterCard ICA
- UnionPay: 6 + Acquirer Union Pay Id
- Discover: 7 + Acquirer Discover Id
- JCB: 9 + Acquirer JCB Id
What is F32 used for?
F32 identifies the institution accepting the transaction, i.e. the merchant's acquiring bank. Thanks to this field, the card-issuing bank understands which bank's POS terminal or ATM the transaction came from. This information is required to match the transaction with the correct bank during clearing, settlement, commission sharing, and chargeback processes.
Difference from F33
Another field often confused with F32 is F33 (Forwarding Institution Identification Code). F32 shows the institution accepting the transaction, while F33 shows the institution forwarding the message to the network. If a bank sends transactions directly to the network, the two fields may have the same value. If transactions are sent through an intermediary institution or processor, F33 contains the code of that intermediary institution.
Structure of the value
As seen in the list above, the first digit of the F32 value indicates which network the transaction belongs to. The following digits contain the identification number assigned to the merchant's acquiring bank on that network. For domestic transactions, this number is based on the bank's TCMB number. For international brands, the member number the bank received from the relevant card brand is used instead.
Points to watch in integration
F32 is a variable-length field. Filling in the value incorrectly can cause the transaction to be routed to the wrong bank or fail to match during clearing. For this reason, when a new card brand or network is added, the F32 format must be tested against that network's specification.
