Why might a US bank reject an incoming international wire transfer?

An incoming international wire transfer can be rejected for various reasons. It mostly has to do with risk & compliance. The bad news is that in 99% of the cases, the reason why an incoming transaction was rejected would not be made known to you or the sender. That is just how the world of banking works. They do this because letting you know the reason would presumably let the outside world figure how what transactions are flagged and how. With such discovery, loopholes can be found and abused.

Each bank in the correspondent banking chain has risk and anti-money laundering compliance rules. Any one of these rules could have been triggered (could very likely be more than one), and the bank’s compliance will determine manually (rejections/returns are usually referred manually), and it will be determined that the bank is not willing to accept (credit) such an inwards transfer. The reason would most likely be shared in a general method with the correspondent bank, and the inward wire credit would not be accepted.

The sender can request the reason for rejection, but as I cited, 9 out of 10 times, you would not be shared with the originator.