Inadvertent error.
(B) Inadvertent error. If a bank fails to enter a liability in the books of the activity that produces ECI before the close of the day on which the liability was incurred, the liability may be treated as a U.S. booked liability only if, under the facts and circumstances, the taxpayer demonstrates a direct connection or relationship between the liability and the activity that produces ECI and the failure to enter the liability in those books was due to inadvertent error.