The Lower Consecutive Offline Limit refers to the maximum number of consecutive offline transactions allowed by the ICC (Integrated Circuit Card) application, as set by the issuer (card-issuing bank), on a terminal that can carry out online transactions.
It is 1 byte of data in tag 9F14.
The purpose of LCOL
LCOL ensures that the card communicates with the bank at regular intervals. If the card makes many offline transactions, the bank can only learn about the card's activity at the clearing stage. Sending the transaction online when LCOL is exceeded gives the bank the opportunity to check the card's status and block it if necessary.
Example
Suppose a card's LCOL value is 3. If the card has completed three transactions offline since its last online transaction, then on the fourth transaction, if the terminal can go online, the transaction is sent to the bank. When the bank approves the transaction, the counter is reset and the card can make offline transactions again.
Relationship with TVR
When LCOL is exceeded, the terminal sets the “lower consecutive offline limit exceeded” bit in the fourth byte of the TVR. This bit is evaluated together with the action codes so that the transaction is sent online.
Practice in Türkiye
In Türkiye, most banks see offline transactions as risky, so they configure their cards and terminals to process the vast majority of transactions online. In this case, the LCOL and UCOL values are less decisive in practice.
