Online transactions require an internet connection. In situations where the internet is not
available, for example, due to an outage, merchants can continue to take credit card payments
using offline transactions. An offline authorization is an authorization request for which you
do not receive an immediate confirmation about the availability of funds.
Offline authorizations have a higher level of risk than online transactions because they do
not provide fund availability confirmations or set aside the funds for later capture. Further,
it can take up to 5 days to receive payment confirmations for offline transactions. To
mitigate this risk, merchants may choose to fulfill orders only after receiving payment
confirmations.