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AAP: Same Day ACH, IAT, and Emerging Payments

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Same Day ACH, IAT, and Emerging Payments

Same Day ACH

Same Day ACH runs on the existing network through three daily windows:

  1. File by 10:30 a.m. ET, settled by 1:00 p.m. ET
  2. File by 2:45 p.m. ET, settled by 5:00 p.m. ET
  3. File by 4:45 p.m. ET, settled by 6:00 p.m. ET

The per-entry limit is $1,000,000 for both credits and debits, and the Effective Entry Date must equal the processing date. Most SEC codes qualify; IAT and non-dollar entries (COR, ENR, ACK/ATX, DNE) do not. Operators charge a small per-entry fee, and returns of Same Day entries can move in a later window the same day - a genuine same-day round trip.

IAT

The International ACH Transaction code applies where the Originator, Receiver, or funds involve a location outside the U.S. Testable features: each participant makes the IAT determination; seven mandatory addenda records; a Foreign Payment Amount in foreign currency plus a Transaction Type Code and ISO country code; processing through a gateway operator; mandatory OFAC screening; and returns under R80–R85.

Emerging payments

RTP and FedNow are credit-only, irrevocable, 24/7/365 systems with immediate finality - the opposite of ACH's return window. Request for Payment messages, ISO 20022 formatting, APIs, and tokenized account numbers are reshaping how ACH and real-time rails interact.

Traps

Applying Same Day windows to IAT; reading the dollar cap as per file rather than per entry; expecting a Same Day debit to be returnable only in the next day's ordinary cycle.

Rule of thumb: Same Day ACH changes when an entry moves, never whether it can be returned.