ACH credit or debit? Follow who starts it.
A push, a pull and the permission behind each: a practical guide to the direction of a bank payment.
Source-checked guide
LEARN / PAYMENT RAILS
Different rails.
Different rules of the road.
The button on your screen tells only part of the story. Follow the institutions, the messages and the movement of funds.
A GOOD PLACE TO BEGIN
Follow a reading path.
THE INTERACTIVE FIELD GUIDE
A payment has a path.
Let’s follow it.
Choose a rail. Walk through the stages.
See who does what along the way.
A purchase at checkoutApproval now. Settlement follows.
Message flowSIMPLIFIED MODEL / U.S. CONTEXT
01MerchantAccepts the purchase
02Processor / acquirerConnects the merchant
03Card networkRoutes the request
04IssuerMakes the decision
01
First, a question. Can this payment go through?
The merchant sends a request through its processor and acquirer. The network routes it to the issuer for a decision. Approval is a message, not settlement.
The response travels back to the checkout. This is a simplified four-party card model.
Source: Mastercard · Switching explained ↗Reference checked 19 Sep 2026 · Method
A QUICK REFERENCE
The rail changes the experience.
| Rail | Processing pattern | Everyday context | Ask about |
|---|---|---|---|
| Cards | Authorization, then clearing and settlement | Merchant acceptance and purchases | Merchant payout follows the provider agreement. |
| ACH | Scheduled processing and settlement | Payroll, bills and bank transfers | Bank cutoffs, business days and return rules matter. |
| FedNow | Instant infrastructure, available around the clock | Transfers through participating institutions | Your institution must offer the relevant service. |
| RTP | Individual, real-time final settlement | Credit-push account transfers | A return request does not guarantee recovery. |
U.S. introductory comparison. Sources checked 19 September 2026: Mastercard · Nacha · Federal Reserve Financial Services · The Clearing House . No universal price, payout time or recovery promise is implied.
Card payment: read all three stages
Authorize
The merchant sends a request through its processor and acquirer. The network routes it to the issuer for a decision. Approval is a message, not settlement.
The response travels back to the checkout. This is a simplified four-party card model.
Clear
Clearing exchanges the financial details between acquirer and issuer. These records support account posting, fee assessment and the calculation of settlement positions.
An authorized amount can differ from the final amount, for example when a tip is added.
Settle
The network calculates net positions and facilitates settlement between issuers and acquirers. The merchant’s payout follows its provider agreement; it is a separate timing question.
This shows roles, not a guaranteed payout time. Actual arrangements and timing vary.
Mastercard · Switching explained ↗ACH transfer: read all three stages
Initiate
In this credit example, an employer tells its bank to send pay to an employee. ACH also supports debits, such as authorized bill payments; those follow a different initiation pattern.
A credit sends funds. A debit collects funds under an authorization. This diagram follows a credit.
Process
ACH payments can process on the same business day or be scheduled one or two business days ahead. Submission deadlines and bank processing affect the practical timing.
Same Day ACH is a faster ACH option. It is distinct from the FedNow Service and RTP network.
Settle
ACH uses scheduled settlement windows on business days. A bank may make payroll available early using its own funds; early account availability does not prove settlement already happened.
Returns and corrections depend on the payment and applicable rules. A balance display alone does not explain those rights.
Nacha · The ABCs of ACH ↗FedNow: read all three stages
Initiate
The FedNow Service is payment infrastructure for eligible U.S. depository institutions. A customer uses a service offered by a participating institution.
Participation and customer-facing services vary. The FedNow Service is not a consumer account or app.
Process
Participating institutions can send and receive payments around the clock. Their service providers may handle parts of the connection and processing.
Check the sending bank’s offering, eligibility and customer limits for a specific transfer.
Receive
The Federal Reserve describes immediate access to funds for recipients of payments sent through the service. A network’s availability is different from your bank’s product terms.
This diagram omits technical validation, exception paths and settlement-account arrangements.
Federal Reserve · About FedNow ↗RTP network: read all three stages
Initiate
RTP is a credit-push network: the sender asks their financial institution to initiate a payment. A request for payment is a message, not permission to debit an account.
The Clearing House operates the RTP network. It is a different network from the Federal Reserve’s FedNow Service.
Settle
RTP provides final interbank settlement. A sending institution cannot revoke a payment once submitted, although the network supports a request to return funds.
A request for a return is not a guaranteed reversal or a card chargeback.
Receive
Receiving institutions must generally make funds available immediately, with limited exceptions under RTP rules. Customer services and fees are set by the institution.
Verify the recipient and the bank’s service before sending. This is a simplified role diagram.
The Clearing House · RTP overview ↗GO A LITTLE DEEPER
From tap to transfer.
ACH or wire: ask about the whole journey.
Compare initiation, settlement and availability instead of treating every bank transfer as the same product.
Source-checked guide
Three milestones that changed the payment clock.
A sourced look back at Same Day ACH in 2016, RTP in 2017 and the FedNow launch in 2023.
Source-checked guide
Retry a payment API call without creating a second operation
A developer pattern for stable operation identities, bounded retries, ambiguous outcomes, and reconciliation.
Source-checked guide
Treat payment webhooks as signed, repeated, out-of-order messages
A receiver design for raw-body signature verification, durable intake, deduplication, ordering, and replay-safe effects.
Source-checked guide
Authorization, capture, void, and refund are different state changes
A developer lifecycle for choosing the right operation and waiting for asynchronous outcomes.
Source-checked guide
A request for payment is a message, not the movement of money
A field guide to consent, credit-transfer initiation, settlement, finality, and reconciliation on instant-payment services.
Source-checked guide
Use ISO 20022 remittance data to match invoices, not just move richer text
An accounts-receivable workflow for identifiers, structured remittance, allocation rules, exceptions, and audit trails.
Source-checked guide
What really happens after you tap?
Meet the issuer, the acquirer and the network behind a card payment.
Research draft
FedNow and RTP: two routes to instant.
Different operators. Similar ambitions. Details worth understanding.
Research draft
Pay by bank: what changes at checkout?
Look past the button to the rail, the price and the protection.
Research draft