Another difference is the use of phone numbers and simple email like identifiers in UPI. That doesn’t seem to be part of FedNow itself. What makes UPI very usable is that entering the phone number or a simple UPI id brings up some metadata about the person to confirm that the transfer target is accurate. In FedNow such a layer has to be added by Zelle or similar layer above, it appears.
Well, given that FedNow has nothing to do with UPI, per the parent's comment, and it's about inter-bank settlement, it makes sense for an application layer like Zelle to provide that.
