What is ACH?
The batch network that moves most US bank-to-bank money — how credits, debits and returns actually work.
ACH — the Automated Clearing House — is the network that moves the majority of bank-to-bank payments in the United States: payroll, vendor payments, bill pay, and platform payouts. It settles in batches rather than one payment at a time, which is why it is inexpensive and why it is not instant.
Credits and debits
An ACH credit pushes money from your account to someone else's — a payout to a carrier, a refund to a customer. An ACH debit pulls money from an account you're authorized to draw on — collecting rent, a subscription, an invoice. Both ride the same network; the difference is direction.
Standard vs. Same-Day ACH
Standard ACH settles over one to two business days. Same-Day ACH clears within the same business day if it makes the submission window. Neither runs on weekends or bank holidays — ACH follows the banking calendar.
Returns
Because ACH is not guaranteed at the moment of submission, a payment can come back days later as a return — insufficient funds, a closed account, no authorization. Each carries a return code you should handle distinctly, not as one generic failure.
How DigitalTreasury handles ACH
On DigitalTreasury, ACH is one payment order like any other rail — standard or Same-Day, credit or debit — with typed return handling and a ledger hold placed the moment the payment is created, so your available balance never over-promises money already in flight.
ACH vs. wire transfer: what's the difference?
Both move money bank-to-bank — but speed, cost and reversibility make them very different tools.
ACH return codes explained (R01, R02, R03…)
Why a payment came back — and why 'insufficient funds' and 'account closed' should be different branches in your code.
What is NACHA?
The body that writes the ACH rulebook — and the thresholds every originator has to live under.