I'm not an expert in this area, but from what I have gathered with respect to domestic Fedwire based wire transfers: Fedwire is arguably the main settlement sy

I'm not an expert in this area, but from what I have gathered with respect to domestic Fedwire based wire transfers: Fedwire is arguably the main settlement system used in the US between banks that participate in the federal reserve, when correspondence accounts are not in use. (Even other systems that claim to be settlement systems seem to often end up using FedWire for final settlement). The actual settlement is simply a debit and credit in the bank's accounts with the Fed. But while that does technically settle payment, in practice more information is needed, as the bank's accountants need to know what this was for, so they can keep their accounts up to date. Therefore metadata can be attached to the transfer. Without that it would be more complicated to figure out what exactly just got settled. But when one is trying to send money not just between banks, but between customers of banks, even more metadata is generally needed. You are correct that at least in theory, the field for the target account would clearly who is getting paid. (Obviously the org receiving the wire will often generally need some additional metadata about what the payment is for, in much the same way banks do, hence the use of fields like 4320.) I suspect that the receiving bank's handling is usually mostly automated (especially with larger banks), but that there are some safeguards that sometimes stop things for manual review both for correctness concerns (like making sure the name of beneficiary is even remotely close to the name associated with that account number) and for security considerations (flagging suspicious transactions to have further verification). And of course, if things are incorrect and things are not caught by the safeguards, it requires human effort to fix. The receiving organization's steps seems to often be at least somewhat manual. (But this can vary, orgs that receiving thousands of transfers a day likely automate more than those that receive just a few.) I get the feeling some organizations with the capability of automatically processing most incoming wires simply don't, because having a person look at the incoming wire, and review what the automated processing will do before clicking an "approve processing" button can catch other mistakes, some of which could be a pain to unwind manually.