A change to the Nacha Operating Rules that replaces the definition of an International ACH Transaction (IAT) takes effect on September 18, 2026. Nacha announced the date on September 1. The IAT code is the label that tells banks an ACH payment has a leg outside the United States.

What changed

  • New IAT definitionthe U.S. ACH Network component of an international payment transaction
  • International payment transactiona transfer that originates with, transits through or is delivered to an account at an office of a financial agency outside the United States, or is received from or delivered through a facility of a financial agency outside the United States
  • FromSeptember 18, 2026
  • Whooriginators, third-party senders and service providers, and the banks and credit unions that send and receive ACH payments

Source: Nacha, September 1, 2026 · Checked on September 27, 2026

Why it matters

Nacha says the purpose of the IAT code stays the same: identifying international ACH payments so institutions can meet their compliance obligations. What changes is which payments get the label. Nacha writes that the new wording “could result in some payments previously treated as domestic being identified as IATs, or vice versa”, and that receiving banks may see a change in the number of IAT entries they screen.

The rule changes how payments are classified, not the ACH settlement schedule.

More IAT changes follow:

Timeline

  1. September 18, 2026new IAT definition takes effect
  2. January 1, 2027banks and credit unions must keep IAT contacts in the ACH Contact Registry
  3. March 2027 and March 2028further IAT changes, including a new return reason code for sanctions compliance

Source: Nacha · Checked on September 27, 2026

What to do

  • If an ACH payment to or from an account abroad arrives later than a domestic one would, ask your bank whether it was handled as an IAT entry.
  • For how long ordinary domestic ACH takes, see how long does ACH take.
  • Sending money out of the country by wire instead? Compare costs in international wire transfer fees.