Things have improved somewhat since then, with the introduction of Same Day ACH, which provides two additional ACH processing periods each business day. https:

Things have improved somewhat since then, with the introduction of Same Day ACH, which provides two additional ACH processing periods each business day. https://www.nacha.org/rules/same-day-ach-moving-payments-faster-phase-3 https://www.nacha.org/rules/same-day-ach-moving-payments-fas... It's more expensive than regular ACH transactions. The above page seems to indicate the sending bank has to pay the receiving bank 5.2 cents per same day transaction on top of regular ACH fees (that appear to be 0.0185 cents per transaction sent or received for 2020).